JP2001131364A - Material resistant to antifreezing fluid for automotive parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a material resistant to an antifreezing fluid for automotive parts excellent in mechanical properties, especially a impact resistance, heat resistance and chemical resistance and excellent in resistance to calcium chloride. SOLUTION: This material resistant to the antifreezing fluid for automotive parts is composed of (A) a polyolefin-based resin, (B) a rubber-like polymer and (C) a fibrous or an acicular filler having 0.01-1,000 μm mean diameter and 5-2,500 mean aspect ratio (length/diameter).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic resin composition reinforced with a fibrous or acicular filler, a polyolefin resin and a rubbery polymer, preferably a partially or completely crosslinked rubbery polymer. The present invention relates to an antifreeze-resistant automobile part material made of a material and an antifreeze-resistant automobile part formed by molding this material.

[0002]

2. Description of the Related Art A radiator tank, which is an automobile part, uses a thermoplastic resin in consideration of light weight, good workability, and the like. In order to use a thermoplastic resin for a radiator tank, performance such as heat resistance, chemical resistance, and impact resistance is required. That is, the coolant used for cooling the engine circulates around 100 ° C. in a steady state, but the temperature instantaneously rises to around 130 ° C. when the engine stops. Therefore, it is necessary to withstand a coolant at a high temperature, and heat resistance and chemical resistance are required. In addition, impact resistance is required for safety against destruction by impact.

[0003] Currently used materials are polyamide resins. Usually, a material reinforced with glass fiber (GF) is used. This GF reinforced polyamide resin is excellent in heat resistance and impact resistance. However, the currently used polyamide resin has a problem in that it is hydrolyzed by a high-temperature coolant liquid, and its strength is greatly reduced, and the long-term stability is lacking.

Recently, the performance of the engine has been improved and the coolant temperature of the coolant has tended to rise more than the current level. Therefore, the polyamide resin currently used cannot be used as it is, and long-term stability has been substituted. There is a demand for a material with certainty. Further, the polyamide resin has problems such as corrosion due to calcium chloride sprayed as a measure against snow melting, that is, poor calcium chloride resistance, and a new material is also demanded from this viewpoint.

[0005]

SUMMARY OF THE INVENTION In view of the above situation, the present invention does not have the above-mentioned problems, that is, it has excellent mechanical strength, especially excellent impact resistance, heat resistance and chemical resistance. It is an object of the present invention to provide an antifreeze-resistant automobile part material having excellent calcium chloride resistance, for example, a material for a radiator tank.

[0006]

Means for Solving the Problems The present inventors have developed an antifreeze liquid vehicle having excellent mechanical strength, especially excellent chemical resistance such as impact resistance, heat resistance and coolant resistance, and also excellent calcium chloride resistance. In order to develop the component materials, we have studied diligently based on polyolefin resin which is basically excellent in calcium chloride resistance. First, a polyolefin resin alone cannot be used as an antifreeze-resistant automobile part material because of its low mechanical strength, particularly impact resistance and heat resistance.

[0007] Accordingly, studies have been made to increase the strength and heat resistance by coexisting glass fibers. On the other hand, an antifreeze-resistant automotive part material comprising glass fiber and a polyolefin resin is disclosed in Japanese Patent Application Laid-Open No. 10-139892. That is, the average fiber length is 1 to 1 in the polypropylene resin.
A radiator tank in which 6 mm glass fiber, that is, long fiber GF is dispersed is disclosed.

[0008] This patent application is characterized in that it is a molded product composed of long fibers (long fibers GF) as glass fibers. By blending the glass fiber with the polyolefin resin, the impact resistance and the heat resistance are certainly improved.
In addition, a molded product using the long fiber GF as a reinforcing material is usually about 0.3 mm.
The impact resistance and the heat resistance, especially the impact resistance, are further improved as compared with a molded product using a short fiber of short mm (short fiber GF) as a reinforcing material.

However, merely coexistence of a polyolefin resin and glass fiber cannot provide mechanical strength characteristics in a practical sense. The reason for this is that when molding a material from a composition consisting of a polyolefin-based material and glass fiber alone, the glass fiber is oriented and the mechanical strength differs in the vertical and horizontal directions with respect to the molding direction. Occurs.

Accordingly, it has been found that when this is used as an antifreeze-resistant automobile part material, the molded product is not sufficiently improved in destruction by impact and does not become a material having practical characteristics. As a result of further study following this result,
By coexisting a rubber-like polymer, preferably a partially or completely cross-linked rubber-like polymer, with the polyolefin resin and glass fiber, the mechanical strength, especially the impact resistance, is further greatly improved and in a practical sense. Sufficient strength can be obtained.

That is, the present inventors have found that damage due to impact is small and the material has practically usable characteristics, and the present invention has been completed. Further, in addition to glass fibers, fibrous fillers such as carbon fibers and polyacrylonitrile (PAN) fibers or needle-like (whisker-like) fillers such as potassium titanate, magnesium oxysulfate, and aluminum borate having a specific shape are also used as rubber-like polymers. The present invention has been found to be a material suitable for an antifreeze-resistant automobile part when a rubber polymer, preferably partially or completely crosslinked, is coexisted, and the present invention has been completed.

The present invention comprises a thermoplastic resin composition reinforced with a fibrous or acicular filler, the composition comprising:
At least (A) a polyolefin-based resin, (B) a rubbery polymer, and (C) an average diameter of 0.01 to 1000 μm.
m and the average aspect ratio (length / diameter) is 5
An antifreeze-resistant automobile part material comprising a fibrous or needle-shaped filler of 2500 and an antifreeze-resistant automobile part made of a molded product of the material.

It is preferable that the rubbery polymer is partially or completely crosslinked. The reason for this is that when the rubbery polymer is not crosslinked, the antifreeze-resistant automobile part material of the present invention is used. When molding, the rubber-like polymer is oriented in the same direction as the glass fiber stretched in the flow direction of the resin composition, but when this rubber-like polymer is cross-linked,
The shape of the rubber-like polymer in the antifreeze-resistant automotive part material of the present invention is maintained in the molded article without being stretched in the flow direction, and the rubber-like polymer is not oriented even if the glass fiber is oriented. For this reason, it leads to a great increase in mechanical strength, especially impact resistance.

Further, the main application of the antifreeze-resistant automobile part material of the present invention is used at a high temperature like a radiator tank. At this time, the rubbery polymer that is not crosslinked generally has a low melting point, and is in a molten state at a high temperature, does not exhibit rubbery elasticity, and has a small reinforcing effect. On the other hand, the crosslinked rubber-like polymer does not melt at a high temperature, exhibits rubber-like elasticity, and also has an excellent reinforcing effect.

The antifreeze-based automotive parts materials (particularly, radiator tanks, water valve materials, etc.) of the present invention are not only resistant to antifreeze containing ethylene glycol as a main component at high temperatures, but also have a mechanical strength (resistance to antifreeze). Impact resistance, rigidity, etc.) and the road deicing agent must have chemical resistance to calcium chloride. The antifreeze-resistant automobile part material of the present invention and an antifreeze-resistant automobile part comprising a molded product of the material. Is also satisfied.

The antifreeze-resistant automobile part made of a molded article of the antifreeze-resistant automobile part material of the present invention is an automobile part through which cooling water flows. Examples of this include a radiator tank, a water pump housing, a water pump impeller, a water valve, a radiator pipe, a heater tank, and the like. Among them, radiator tanks and radiator pipes require high chemical resistance and heat resistance because high-temperature antifreeze is used, and are particularly preferable because the characteristics of the antifreeze-resistant automobile part material of the present invention can be utilized.

Hereinafter, the present invention will be described in detail. First, each component of the present invention will be described in detail. The polyolefin-based resin as the component (A) in the antifreeze-resistant automobile part material of the present invention will be described. In the present invention, the polyolefin-based resin is roughly composed of a polyethylene-based resin, a polypropylene-based resin, or a mixture of a polyethylene-based resin and a polypropylene-based resin.

As the polyethylene resin, high-density polyethylene (HDPE), low-density polyethylene (LDP)
E), linear low density polyethylene (LLDPE), copolymer of acrylic vinyl monomer and ethylene (EE
A, EMMA, etc.) or a copolymer of a vinyl acetate monomer and ethylene (EVA). However, among these, high density polyethylene (HD
PE), low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) are particularly preferred because of their high heat resistance and availability at low cost. These polyethylene resins may be used alone or in combination of two or more.

When high density polyethylene (HDPE) is used, its density generally ranges from 0.930 to 0.970.
g / cm ³ , and the melt flow rate (MFR) measured at 190 ° C. under a load of 2.16 kg is 0.0
It is preferably in the range of 5 to 100 g / 10 minutes.

When low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE) is used, its density is generally 0.900 to 0.930 g /
in the range of cm ^3, 190 ° C., a melt flow rate measured at 2.16kg load (MFR) is 0.05
It is preferably in the range of 100 g / 10 minutes. If the melt flow rate exceeds 100 g / 10 min, the mechanical strength and heat resistance of the antifreeze-resistant automobile part formed from the antifreeze-resistant automobile part material of the present invention are insufficient, and 0.05 g / 10 min. If it is smaller, the fluidity is poor when molding the antifreeze-resistant automotive part material of the present invention, and the molding processability is undesirably reduced.

Examples of the polypropylene resin include homopolypropylene, copolymer resins (including block and random) of propylene with other α-olefins such as ethylene, butene-1, pentene-1, and hexene-1. be able to.

The polypropylene resin used as a raw material of the antifreeze-resistant automobile part material of the present invention has a temperature of 230 ° C.
2. Melt flow rate (M
FR) is preferably in the range of 0.1 to 100 g / 10 minutes. If the melt flow rate exceeds 100 g / 10 min, the mechanical strength and heat resistance of the antifreeze-resistant automobile part formed from the antifreeze-resistant automobile part material of the present invention are insufficient, and 0.1 g / 10 min. If it is smaller, the fluidity is poor when molding the antifreeze-resistant automotive part material of the present invention, and the molding processability is undesirably reduced.

The polyolefin resin used for the antifreeze-based automotive part material of the present invention comprises a polyethylene resin and / or a polypropylene resin as described above.
When used as an antifreeze-resistant automotive part material, particularly when used at high temperatures such as radiator tanks, polypropylene-based resins are more preferable because of their high heat resistance.

However, homopolypropylene generally tends to be oxidatively decomposed and has a tendency to decrease in mechanical strength due to a decrease in molecular weight during long-term use. On the other hand, polyethylene generally has a tendency to crosslink without oxidative decomposition and to maintain or improve mechanical strength. For this reason, in automobile parts requiring durability, it is preferable to use homopolypropylene and polyethylene in combination, or use or use propylene and ethylene-based random or block polymers.

Next, the rubbery polymer which is the component (B) of the antifreeze-resistant automobile part material of the present invention will be described. The rubbery polymer of the present invention has a glass transition temperature (Tg) of -30.
C. or lower, and such rubbery polymers include, for example, diene rubbers such as polybutadiene, poly (styrene-butadiene), and poly (acrylonitrile-butadiene); saturated rubber obtained by hydrogenating the diene rubber; isoprene; Examples include rubber, chloroprene rubber, acrylic rubber such as polybutyl acrylate, and ethylene / α-olefin copolymer rubber.

Among these, an ethylene / α-olefin copolymer rubber mainly composed of ethylene and α-olefin is most preferred. The reason for this is that ethylene
The olefin-based copolymer rubber has good compatibility with the polyolefin-based resin used as the component (A) of the antifreeze-resistant automobile part material of the present invention, and the ethylene / α-olefin-based copolymer rubber is interfaced with the polyolefin-based resin. This is due to adhesion and high mechanical strength such as impact resistance.

The ethylene / α-olefin copolymer rubber will be described in more detail.
Ethylene-α-olefin-based copolymer rubber containing α-olefin as a main component is more preferable. Α having 3 to 20 carbon atoms
-As the olefin, for example, propylene, butene-
1, pentene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1, and the like.

These α-olefins may be used alone or in combination of two or more. Further, a copolymer component may be included as the third component. Examples of the copolymerization component of the third component include conjugated dienes such as 1,3-butadiene and isoprene, and non-conjugated dienes such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, and ethylidene norbornene.

Ethylene / α containing a third component copolymerization component
Examples of the olefin-based copolymer rubber include ethylene-propylene-conjugated or non-conjugated diene terpolymer rubber (EPDM). However,
Automotive parts are often used outdoors and preferably have good weather resistance.

An ethylene / α-olefin copolymer rubber containing a conjugated or non-conjugated diene is not preferable because of poor weather resistance as compared with an ethylene / α-olefin copolymer rubber containing no conjugated or non-conjugated diene. . The present invention does not exclude an ethylene / α-olefin-based copolymer rubber containing a conjugated or non-conjugated diene, but an ethylene / α-olefin-based copolymer rubber containing no conjugated or non-conjugated diene is more preferable. More preferred.

Examples of this are ethylene and hexene-
Preferred examples include 1,4-methylpentene-1 or an ethylene / α-olefin copolymer rubber with octene-1. Among these, an ethylene / α-olefin copolymer rubber of ethylene and octene-1 is particularly preferred. The reason is that it has excellent weather resistance and rubber elasticity even in a small amount. The ethylene / octene-1 copolymer rubber suitably used as the component (B) in the antifreeze-resistant automobile part material of the present invention is preferably produced using a metallocene catalyst.

Even if the rubbery polymer as the component (B) is not cross-linked, the effect of improving the impact resistance can be seen by blending it, and it is not essential to cross-link. However, it is preferred that they are partially or completely crosslinked.

The reason is that, as described above, when the antifreeze-resistant automobile part material of the present invention is formed and processed, it is stretched and oriented in the flow direction of the resin composition, but when the rubbery polymer is crosslinked, In order to maintain the shape of the rubber-like polymer in the antifreeze-resistant automobile part material of the present invention in the molded article without being stretched in the flow direction, even if the filler is oriented, the rubber-like weight body relaxes the directionality. That's why.
Further, the crosslinked rubbery polymer exhibits rubbery elasticity even at a high temperature. Therefore, an antifreeze-resistant automobile part material using a crosslinked rubbery polymer as compared with non-crosslinked one becomes an automobile part having extremely high impact resistance.

In the case of crosslinking, the ratio of the crosslinked rubbery polymer (rubbery polymer that does not dissolve in the solvent) in the total rubbery polymer present in the antifreeze-resistant automobile part material is defined by the degree of crosslinking. Then, the degree of crosslinking is preferably 20% or more. Further, it is more preferably at least 50%. Next, the fibrous or acicular filler which is the component (C) of the antifreeze-resistant automobile part material of the present invention will be described.

The fibrous or acicular filler (C) of the present invention has an average diameter of 0.01 to 1000 μm.
m, preferably 0.1 to 500 μm, more preferably 1 to 100 μm, and most preferably 5 to 50 μm, and an average aspect ratio (length / diameter) of 5 to 25 μm.
00, preferably 10 to 1000, particularly preferably 50 to 1000, without particular limitation.

If the average diameter is less than 0.01 μm, the reinforcing effect is small and the effect of improving mechanical strength is not sufficient.
If it exceeds 1000 μm, the dispersibility decreases, and similarly, the effect of improving the mechanical strength is not sufficient. If the average aspect ratio (length / diameter) is less than 5, the anisotropy is insufficient and the reinforcing effect is small. On the other hand, if it exceeds 2,500, the fluidity during molding is not sufficient and there is a problem in molding. Wake up.

As the fibrous filler, for example, cotton,
Natural fiber such as silk, wool or hemp, regenerated fiber such as rayon or cupra, semi-synthetic fiber such as acetate or promix, synthetic fiber such as polyester, polyacrylonitrile, polyamide, aramid, polyolefin, carbon or vinyl chloride, glass or Examples thereof include inorganic fibers such as asbestos and metal fibers such as SUS, copper and brass.

Examples of the needle-like filler include potassium titanate, magnesium oxysulfate, aluminum borate, wollastonite, sebiolite, zonotolite, phosphate fiber, dawsonite, gypsum fiber, MOS, needle-like calcium carbonate, and tetrapot type oxide. Whiskers made of zinc, silicon carbide or silicon nitride can be used.

As the fibrous or acicular filler as the component (C) of the present invention, any of the above-mentioned materials can be arbitrarily selected and used in one kind or in combination of a plurality thereof. As glass fiber (G
F), carbon fiber (CF), magnesium oxysulfate whisker and the like are preferable, and among them, glass fiber and carbon fiber are preferable in terms of impact strength, rigidity and heat resistance.

The fibrous or acicular filler which is the component (C) of the present invention is as described above. Among glass fibers and carbon fibers which are preferable in terms of performance, glass fibers can be obtained at low cost from the market. Particularly preferred. However, carbon fiber is expensive compared to glass fiber, but has an effect of increasing rigidity, so that glass fiber can be used as a main reinforcing agent and carbon fiber can be used as an auxiliary agent.

When glass fibers are used, ordinary commercially available ones are used. Commercially available glass fibers are E
Glass, S glass, C glass, AR glass, etc.
Any of these can be used. In general, the diameter of glass fiber is preferably 10 to 30 μm. The glass used is preferably glass that has been pretreated, for example, with a silane coupling agent, in order to increase the adhesion to the resin.

When a fibrous filler is used, short fibers GF or CF can also be used.
F or CF shows higher physical properties and is more preferable.
The antifreeze-resistant automobile part material of the present invention comprises at least (A) a polyolefin-based resin, (B) a rubbery polymer, and (C) an average diameter of 0.01 to 1000 μm and an average aspect ratio of 5 to 5 μm. 2500 fibrous or acicular fillers, but if necessary, other components,
For example, polymers other than polyolefin resins, softeners,
It is possible to contain a powdery inorganic filler and a plasticizer.

As other polymers, those which improve the interfacial adhesion between the fibrous or acicular filler and the polyolefin resin are particularly effective for improving the impact resistance. As such a material, it is preferable to coexist, for example, a maleic acid modified or copolymerized polyolefin, an acrylic acid modified or copolymerized polyolefin, a fumaric acid modified or copolymerized polyolefin, or the like.

This material is particularly effective when glass fiber is used as the fiber. In addition to polymers that improve the adhesion between such fillers and polyolefin resins,
It is also possible to allow other polymers to coexist at a level that does not impair the properties of the antifreeze-resistant automotive part material of the present invention.

As a softener, a process oil such as a paraffin-based or naphthene-based process oil can be used. When coexisting with a softener, the rigidity tends to decrease slightly, but has the effect of further improving impact resistance. Examples of the powdery inorganic filler include calcium carbonate, magnesium carbonate, silica, carbon black, titanium oxide, clay, mica, talc, magnesium hydroxide, and aluminum hydroxide.

Examples of the plasticizer include phthalic acid esters such as polyethylene glycol and dioctyl phthalate (DOP). Also, other additives, for example, organic and inorganic pigments, heat stabilizers, antioxidants,
UV absorbers, light stabilizers, flame retardants, silicone oils, antiblocking agents, foaming agents, antistatic agents, antibacterial agents and the like are also suitably used.

The antifreeze-based automotive part material of the present invention comprises:
As described above, at least (A) a polyolefin-based resin,
(B) a rubbery polymer, and (C) an average diameter of 0.01
１０００1000 μm and an average aspect ratio of 5-2
500 fibrous or acicular fillers, and the proportion of each component in the thermoplastic resin molded product is such that component (A) is 90 to 20% by weight, component (B) is 5 to 40% by weight, (C) component is 5-40 weight%, Preferably,
The component (A) is 80 to 30% by weight, and the component (B) is 10% by weight.
-30% by weight, component (C) is 10-40% by weight,

More preferably, the component (A) is 70 to 4
0% by weight, the component (B) is 10 to 25% by weight, and the component (C) is 20 to 35% by weight. When the polyolefin-based resin as the component (A) exceeds 90% by weight, the amounts of the rubbery polymer and the filler are small, resulting in low mechanical strength. When the amount is less than 20% by weight, when the antifreeze-resistant automobile part material of the present invention is formed, the fluidity is low and the forming processing becomes difficult.

When the content of the rubbery polymer as the component (B) is less than 5% by weight, the mechanical strength of the antifreeze-resistant automobile part obtained by molding the antifreeze-resistant automobile part material of the present invention, in particular, the anti-freeze-resistant automobile part. Impact resistance does not reach the practical range. When the content exceeds 30% by weight, rubber-like elasticity increases as a result, and the rigidity and the like of the antifreeze-resistant automobile part obtained by molding the antifreeze-resistant automobile part material of the present invention are reduced.

If the amount of the filler (C) is less than 5% by weight, the rigidity of an automobile part obtained by molding the antifreeze-resistant automobile part material of the present invention is undesirably low.
When the content exceeds 40% by weight, the rigidity of the automobile part obtained by molding the antifreeze-resistant automobile part material of the present invention is increased and the impact resistance is also high, which is a preferable direction, but the appearance of the molded article is poor and the commercial value is low. It is not preferable because it decreases.

Next, a method for producing an antifreeze-resistant automobile part material of the present invention and a preferable molding method thereof will be described.
The antifreeze-based automotive part material of the present invention generally comprises a polyolefin resin (I) and a component (A) and a polyolefin resin (B).
A thermoplastic elastomer comprising a rubbery polymer, preferably a partially or completely crosslinked rubbery polymer, and (I)
I) A filler as the component (C), preferably a fibrous filler, particularly preferably glass fiber and, if necessary, a polyolefin-based resin or the like for adjusting the concentration of the rubber-like polymer and the filler. The resulting pellets are used as the antifreeze-resistant automotive part material of the present invention, and this material is processed by injection molding or the like.

However, in the method of preliminarily blending with a twin-screw extruder or the like, a filler having a low strength and a specific shape is crushed when passing through the extruder and the aspect ratio is reduced. In this case, a molded product having the desired mechanical strength may not be obtained.

When a fibrous filler, preferably glass fiber, is used as the component (C), the following method can be preferably employed. That is, (I) a thermoplastic elastomer composed of a polyolefin resin as the component (A) and a rubbery polymer as the component (B), preferably a partially or completely crosslinked rubbery polymer, and (II) fibers The present invention comprises kneading the fibrous filler itself or the fibrous filler solidified with a sizing agent or the like and the polyolefin resin and the like in order to adjust the concentration of the rubber polymer and the filler if necessary. The antifreeze-based automobile parts are obtained by a method such as direct injection molding of the kneaded material.

In this case, since the kneading is performed only once, the aspect ratio becomes closer to the aspect ratio of the raw material as compared with the method of blending with a twin screw extruder and further performing injection molding.
It becomes an antifreeze-based automotive part with high mechanical strength. Particularly preferred methods include (I) a thermoplastic elastomer pellet comprising a rubbery polymer, preferably a partially or completely crosslinked rubbery polymer and a polyolefin resin, and (II) a bundle of glass fibers. While extruding and coating the polyolefin-based resin into pellets, pellets containing fibrous filler of the same length as the pellet length (referred to as long fiber pellets) and, if necessary, blending the pellets with the polyolefin-based resin pellets for composition adjustment The antifreeze-resistant automotive parts material of the invention is used, and the material comprising this blend is directly injection molded.

In the case of fibrous fillers, especially glass fibers,
As the acid-modified polyolefin-based resin added in order to increase the adhesion to the polyolefin-based resin, one added to one or both of a thermoplastic elastomer and a polyolefin-based resin pellet is used. A crosslinked thermoplastic elastomer composed of a partially or completely crosslinked rubbery polymer and a polyolefin resin preferably used as the component (B) is produced, for example, as follows.

Preferably, an ethylene / α-olefin copolymer rubber mainly composed of ethylene and α-olefin,
It is produced by heat-treating a polyolefin-based resin, a crosslinking agent and a crosslinking assistant with a twin-screw extruder, a Banbury mixer, or the like. The crosslinking agent preferably used in this case includes a radical initiator such as an organic peroxide and an organic azo compound.

Specific examples of the radical initiator include:
1,1-bis (t-butylperoxy) -3,3,5-
Trimethylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) ) Cyclododecane, 1,1-bis (t-butylperoxy) cyclohexane,

2,2-bis (t-butylperoxy) octane, n-butyl-4,4-bis (t-butylperoxy) butane, n-butyl-4,4-bis (t-butylperoxy) ) Peroxyketals such as valerate; di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, α, α′-bis (t-butylperoxy-m-isopropyl) benzene, α, α'-bis (t-butylperoxy) diisopropylbenzene,

2,5-dimethyl-2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-
Dialkyl peroxides such as 2,5-bis (t-butylperoxy) hexine-3; acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5 -Trimethylhexanoyl peroxide, benzoyl peroxide,

Diacyl peroxides such as 2,4-dichlorobenzoyl peroxide and m-trioyl peroxide; t-butylperoxyacetate;
-Butylperoxyisobutyrate, t-butylperoxy-2-ethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate,
Di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane,

Peroxyesters such as t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate and cumylperoxyoctate; and t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide Oxide, 2,5-dimethylhexane-2,5
And hydroperoxides such as dihydroperoxide and 1,1,3,3-tetramethylbutyl peroxide.

Among these compounds, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl -2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 are preferred.

These radical initiators are ethylene • α
-Olefin copolymer and polyolefin resin 100
0.02 to 3 parts by weight, preferably 0.05 to 3 parts by weight
Used in an amount of １1 part by weight. The level of crosslinking is mainly determined by this amount. If the amount is less than 0.02 parts by weight, the crosslinking is insufficient, and if the amount exceeds 3 parts by weight, the crosslinking rate is not greatly improved, so that it is not a preferable direction.

Examples of the crosslinking aid include divinylbenzene, triallyl isocyanurate, triallyl cyanurate,
Diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate,
Trimethylolpropane triacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, P-quinone dioxime, P, P'-dibenzoylquinone dioxime, phenylmaleimide, allyl methacrylate, N , N'-m-
Phenylene bismaleimide, diallyl phthalate, tetraallyloxyethane, 1,2-polybutadiene and the like are preferably used. These crosslinking aids may be used in combination of two or more.

The crosslinking aid is used in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, per 100 parts by weight of the ethylene / α-olefin copolymer and the polyolefin resin. If the amount is less than 0.1 part by weight, the crosslinking rate is low, which is not preferable. If the amount exceeds 5 parts by weight, the crosslinking ratio is not greatly improved, which is not a preferable direction. It is preferable to use a crosslinking agent and a crosslinking auxiliary as described above as a method of crosslinking,
In addition, a phenol resin or bismaleimide can be used as a crosslinking agent.

Next, a method for producing long fiber pellets, that is, a fibrous filler having the same length as the pellet length will be described using glass fibers as an example. The production method is, for example, a method of dipping a roving of glass fiber in a molten polyolefin-based resin and then pelletizing to a predetermined length or a method generally called a pultrusion method. There is a method in which a polyolefin resin is extruded from the side by an extruder while being aligned, and the surface of the glass fiber is extruded and coated with the polyolefin resin to form a pellet.

The long fiber pellets thus obtained are:
Usually, the size is 2 to 100 mm, preferably 3 to 50 mm, more preferably 5 to 20 mm. The long fiber pellet contains glass fiber having the same length as the pellet length. By mixing and injecting such long glass fiber-containing pellets, thermoplastic elastomer pellets, and, if necessary, polyolefin-based pellets, the average fiber length of the glass fibers in the molded article that is an antifreeze-resistant automobile part is obtained. Is 0.5 to 10 mm as a result.

As a preferable method for producing a molded article which is an antifreeze-resistant automobile part of the present invention, in addition to the above-mentioned method, roving of a fibrous filler, for example, glass fiber, may be carried out using a sizing agent, for example, latex, low molecular weight polymer. It can also be produced by mixing and solidifying with a material or the like, cutting into a size of 2 to 100 mm, pellets of the thermoplastic elastomer, and if necessary, polyolefin-based pellets, followed by injection molding.

In order to obtain an antifreeze-resistant automobile part from the antifreeze-resistant automobile part material of the present invention, it is possible to carry out molding by extrusion molding, compression molding or the like in addition to the injection molding described above. The automotive parts obtained from the antifreeze-resistant automotive parts material of the present invention thus manufactured are products having excellent mechanical strength, especially excellent in impact resistance, rigidity, heat resistance, and chemical resistance (coolant liquid resistance). Become.

[0070]

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In these examples and comparative examples, the test methods used for evaluating various physical properties, and the production methods of the thermoplastic elastomer used for the raw materials and the blending are as follows.

1. Test method (1) Tensile strength Measured at 23 ° C. by a method according to JIS K6251. (2) Bending strength Measured at 23 ° C. by a method according to JIS K6758. (3) Flexural modulus Measured at 23 ° C. by a method according to JIS K6758. (4) Izod impact strength Measured at 23 ° C. by a method according to JIS K6758. (V notch, 1/4 inch test piece)

(5) Heat resistance (HDT) Measured in accordance with JIS K7207. 18.
6kg load, 1/8 inch thickness, heating rate 120 ° C
/ Hr. (6) Drop weight impact strength Using a drop weight impact tester (manufactured by Toyo Seiki Seisaku-sho), tip diameter of drop weight: 13.6 mm, weight: 6.5 kg, drop height: 1
00cm, holder diameter: 50mm, specimen thickness: 3m
m, temperature: 23 ° C., humidity 50%, total absorbed energy was measured. This evaluation is a practical evaluation of impact resistance. This is a test method in which the difference between the vertical and horizontal directions due to the orientation of the filler or the rubbery polymer in the molded article is taken into account. Total absorbed energy indicates practical strength.

(7) Antifreeze test A 50% aqueous antifreeze solution containing ethylene glycol as a main component was heated to 130 ° C., and a test piece was immersed in the solution for a predetermined time, and then the physical properties were measured. (8) Calcium chloride resistance evaluation test A rectangular test piece (1/8 inch) in a saturated water-absorbing state was kept bent under a constant stress, and a 30% by weight aqueous calcium chloride solution was applied thereto. After standing in a hot air dryer, the surface condition of the test specimen is observed. (-) No cracks (+) → (+++) Cracks occur more severely to the right

(9) Filler Average Diameter, Aspect Ratio The number average particle diameter of the filler was determined by an electron microscope, while the filler length was determined by an optical microscope, and the aspect ratio was calculated from the length / diameter ratio. That is, the cross section of each filler is assumed to be a circle, and the arithmetic average of the major axis and the minor axis is defined as the average diameter of each filler. And number average particle diameter was calculated | required by arithmetic mean of the average diameter of 100 fillers. The average length of the above-mentioned filler was similarly obtained as the number average length. (10) Degree of Crosslinking 0.5 g of the crosslinked thermoplastic elastomer was added to xylene 200
Reflux in ml for 4 hours. The solution was filtered with a filter paper for quantification, the residue on the filter paper was vacuum-dried, quantified, and calculated as the ratio (%) of the weight of the residue to the weight of the rubbery polymer in the crosslinked thermoplastic elastomer.

2. Raw Materials (1) Rubbery polymer (a) Ethylene / octene-1 copolymer Produced by a method using a metallocene catalyst described in JP-A-3-1630088. The ethylene / octene-1 composition ratio of the copolymer was 72/28 (weight ratio) (referred to as TPE-1). (B) Ethylene / propylene / dicyclopentadiene copolymer JP-A-3-1630088 It was produced by a method using a metallocene catalyst described in the gazette. The composition ratio of ethylene / propylene / dicyclopentadiene in the copolymer is 72/2.
4/4 (weight ratio). (Referred to as TPE-2)

(2) Olefin-based resin (a) Polypropylene Isotactic homopolypropylene (trade name: MA03) manufactured by Nippon Polychem Co., Ltd. (referred to as PP) (b) Ethylene (E) -propylene (PP) copolymer resin -1 Nippon Polyolefin Co., Ltd., block E-PP resin [E / PP = 6/94 (weight ratio)] (trade name: PM97
0A) (referred to as EP-1) (C) Ethylene (E) -propylene (PP) copolymer resin-2 Random E-PP resin manufactured by Japan Polyolefin Co., Ltd. [E / PP = 7/93 (weight ratio) ] (Product name PM94
0M) (referred to as EP-2) (d) Maleated polypropylene Maleated polypropylene (trade name Admer GF305) manufactured by Mitsui Chemicals, Inc. (referred to as M-PP)

(3) High density polyethylene Suntech HD (trade name: B47, manufactured by Asahi Kasei Corporation)
0) (referred to as HDPE) (4) Radical initiator 2,5-dimethyl-2,5-bis (t-manufactured by NOF Corporation)
Butylperoxy) hexane (trade name Perhexa 25)
B) (referred to as POX) (5) Cross-linking aid Wako Pure Chemical Industries, divinylbenzene (referred to as DVB) (6) Softener (paraffin oil) Idemitsu Kosan, Diana Process Oil (trade name PW-3)
80) (7) Filler

(A) Glass fiber Robe with aminosilane treated by Asahi Fiber (trade name: ER740) (thickness: 13 μm) (b) Carbon fiber Robe with carbon fiber made by Toho Rayon (trade name: HTA-)
12K) (Thickness: 7μ) (c) Magnesium oxysulfate whisker Whisker manufactured by Ube Materials (trade name: Moss Heidi A)

3. Production Method of Crosslinked Thermoplastic Elastomer (1) TPV-1 A twin-screw extruder (40 mmφ, L / D = 47) having an injection port in the center of the barrel was used as an extruder. As the screw, a double screw having a kneading portion before and after the injection port was used. TPE-1 / PP / POX / DVB = 6 /
44.4 / 0.38 / 0.74 (weight ratio) were mixed and melt-extruded at a cylinder temperature of 220 ° C. The degree of crosslinking of the obtained crosslinked thermoplastic elastomer was 82%.

(2) TPV-2 The ratio of TPE-1 / PP / POX / DVB was 55.6 /
A crosslinked thermoplastic elastomer was obtained in the same manner as in (1) except that the ratio was 44.4 / 0.19 / 0.37 (weight ratio).
The degree of crosslinking of this crosslinked thermoplastic elastomer was 55%. (3) Convert TPV-3 TPE-1 / PP / POX / DVB to TPE-1 / EP
A crosslinked thermoplastic elastomer was obtained in the same manner as in (1) except that -1 / POX / DVB was used. The degree of crosslinking of this crosslinked thermoplastic elastomer was 81%.

(4) TPV-4 TPE-1 / PP / POX / DVB is converted to TPE-1 / PP
/ HDPE / POX / DVB and the ratio is 55.6
/33.3/11.1/0.19/0.37 (weight ratio)
A crosslinked thermoplastic elastomer was obtained in the same manner as in (1), except that The degree of crosslinking of this crosslinked thermoplastic elastomer was 85%. (5) Convert TPV-5 TPE-1 / PP / POX / DVB to TPE-2 / PP
A crosslinked thermoplastic elastomer was obtained in the same manner as in (1) except that / POX / DVB was used. The degree of crosslinking of this crosslinked thermoplastic elastomer was almost 100%.

(6) TPV-6 A softener (paraffin oil) was added to the total amount of 100 parts by weight of TPE-1 and PP from the injection port at the center of the extruder.
Was injected in the same manner as in (1) except that 33 parts by weight of was injected to obtain a crosslinked thermoplastic elastomer. The degree of crosslinking of this crosslinked thermoplastic elastomer was 82%.

4. Method for Producing Non-Crosslinked Thermoplastic Elastomer (1) As a TPO-1 extruder, a twin-screw extruder (40 mmφ, L / D = 47) having an inlet at the center of the barrel was used. As the screw, a double screw having a kneading portion before and after the injection port was used. TPE-1 / PP = 55.6 / 44.4 (weight ratio) was mixed and melt-extruded at a cylinder temperature of 200 ° C.

[0084]

Example 1 5% M-PP / 95% PP was extruded from the side with an extruder while a roving of 13 μm thick glass fiber was aligned under tension, and the surface of the glass fiber was extrusion-coated with a polyolefin resin. And cut into pellets having a length of 7 mm to produce long fiber pellets (referred to as GF-1). The aspect ratio of the glass fibers in the long fiber pellet is 538. The ratio of the long fiber pellet to glass / polyolefin resin was 56/44 (weight ratio). Each pellet of GF-1, TPV-1, and PP was
Mix at 3.6 / 36.0 / 10.4 (weight ratio), set the molding temperature to 240 ° C, and use an injection molding machine (Toshiba IS45PNV).
To obtain a molded product. Table 1 shows the final composition of the molded article and the evaluation results.

[0085]

Example 2 A molded product was obtained in the same manner as in Example 1 except that TPV-1 was changed to TPV-2. Table 1 shows the final composition of the molded article and the evaluation results.

[0086]

Example 3 A molded product was obtained in the same manner as in Example 1 except that TPO-1 was changed to TPO-1. Table 1 shows the final composition of the molded article and the evaluation results.

[0087]

Comparative Example 1 The long fiber pellets obtained in Example 1 (GF
-1) and PP pellets were mixed at 53.6 / 46.4 (weight ratio), and a molded product was obtained in the same manner as in Example 1. Table 1 shows the final composition of the molded article and the evaluation results.

[0088]

Example 4 Each pellet of GF-1, TPV-1, and PP was prepared by mixing GF-1 / TPV-1 / PP = 53.6 / 18.0 /
A molded product was obtained in the same manner as in Example 1 except that the mixture was mixed at 28.4 (weight ratio). Table 1 shows the final composition of the molded article and the evaluation results.

[0089]

Example 5 Each pellet of GF-1, TPV-1, and PP was obtained by mixing GF-1 / TPV-1 / PP = 35.7 / 36.0 /
A molded product was obtained in the same manner as in Example 1 except for mixing at 28.3 (weight ratio). Table 1 shows the final composition of the molded article and the evaluation results.

[0090]

Example 6 A molded product was obtained in the same manner as in Example 1 except that TPV-1 was changed to TPV-5. Table 1 shows the final composition of the molded article and the evaluation results.

[0091]

Example 7 The material to be extrusion coated on glass fiber was 5% M-
A long fiber pellet (referred to as GF-2) was produced in the same manner as in Example 1 except that PP / 95% PP was changed to 5% M-PP / 95% EP-1. The ratio of the long fiber pellet to the glass / polyolefin resin is 56/4.
4 (weight ratio). Each pellet of GF-2, TPV-3 and PP was 53.6 / 36.0 / 10.4 (weight ratio)
And molded in the same manner as in Example 1 to obtain a molded product. Table 1 shows the final composition of the molded article and the evaluation results.

[0092]

Example 8 The components and composition of each pellet of GF-1, TPV-1, and PP were GF-1 / TPV-1 / EP-2 = 5.
A molded product was obtained in the same manner as in Example 1 except that the mixture was mixed at 3.6 / 36.0 / 10.4 (weight ratio). Table 1 shows the final composition of the molded article and the evaluation results.

[0093]

Example 9 The material to be extrusion coated on glass fiber was 5% M-
5% M-PP / 71.3% PP / from PP / 95% PP
A long fiber pellet (referred to as GF-3) was produced in the same manner as in Example 1 except that 23.7% HDPE was used.
The ratio of the long fiber pellet to the glass / polyolefin resin was 56/44 (weight ratio). GF-3,
Each pellet of TPV-4 and PP was added to 53.6 / 36.0 /
The mixture was mixed at 10.4 (weight ratio) and molded in the same manner as in Example 1 to obtain a molded product. Table 1 shows the final composition of the molded article and the evaluation results.

[0094]

Example 10 The composition of the pellets was GF-1 / TPV-6.
= 53.6 / 46.4 (weight ratio), and a molded product was obtained in the same manner as in Example 1. Table 1 shows the final composition of the molded article and the evaluation results.

[0095]

[Comparative Example 2] The radiator tank material (33
% Glass short fibers 6,6 nylon) and subjected to an antifreeze test. Table 1 shows the evaluation results.

[0096]

Embodiment 11 A roving of glass fiber having a thickness of 13 μm was cut into 7 mm to obtain a chop. This chop and each pellet of TPV-1 and PP were added to 30.0 / 36.0 /
34.0 (weight ratio), and a twin screw extruder (Toshiba TEM
At -35B), the mixture was extruded and pelletized at a resin temperature of 230 ° C. The diameter of the glass fiber in the pellet is 13 μm and the length is 0.1 mm.
7 mm. The aspect ratio of the glass fibers in the pellet is 54. The pellets were used as a raw material at a molding temperature of 240 ° C. and molded by an injection molding machine (Toshiba IS45PNV) to obtain a molded product. Table 2 shows the final composition of the molded article and the evaluation results.

[0097]

Comparative Example 3 A roving of glass fiber having a thickness of 13 μm was cut into 7 mm and chopped. The chop was further pulverized with a ball mill to obtain ultrashort fibers having an average length of about 100 μm. This ultrashort fiber and each pellet of TPV-1 and PP were mixed at a weight ratio of 30.0 / 36.0 / 34.0, and the resin temperature was adjusted to 23 with a twin-screw extruder (Toshiba TEM-35B).
Extruded and pelletized at 0 ° C. The diameter of the glass fiber in the pellet was 13 μm, and the average length was 42 μm. The aspect ratio of the glass fibers in the pellet is 3.2.

Using the pellets as raw materials, the molding temperature was set to 24.
The temperature was set to 0 ° C., and the product was molded by an injection molding machine (Toshiba IS45PNV) to obtain a molded product. Table 1 shows the final composition of the molded article and the evaluation results.

[0099]

Example 12 5% M-PP / 95% PP was extruded from the side while extruding a roving of carbon fiber having a thickness of 7 μm under tension with an extruder, and the surface of the carbon fiber was extrusion-coated with a polyolefin resin. And cut into 7 mm long pellets to produce long fiber pellets (referred to as CF-1). Aspect ratio of carbon fiber in long fiber pellet is 10
00. The ratio of the carbon fiber / polyolefin resin of the long fiber pellet was 56/44 (weight ratio). Each pellet of CF-1, TPV-1, and PP was used for 19.
The mixture was mixed at 6 / 36.0 / 44.4 (weight ratio), the molding temperature was set to 240 ° C., and the mixture was molded by an injection molding machine (Toshiba IS45PNV) to obtain a molded product. Table 2 shows the final composition of the molded article and the evaluation results.

[0100]

Example 13 Each of magnesium oxysulfate whisker (Moss Heidi), TPV-1, and PP pellets was mixed at 30.0 / 36.0 / 34.0 (weight ratio) and mixed.
The mixture was extruded and pelletized at a resin temperature of 230 ° C. using a screw extruder (Toshiba TEM-35B). The average diameter of the whiskers in the pellets was 0.6, and the average length was 8 μm. The aspect ratio of the whiskers in the pellets is 13. The pellets were used as a raw material at a molding temperature of 240 ° C. and molded by an injection molding machine (Toshiba IS45PNV) to obtain a molded product. Table 2 shows the final composition of the molded article and the evaluation results.

[0101]

[Table 1]

[0102]

[Table 2]

[0103]

According to the present invention, (A) the polyolefin resin,
(B) a rubber-like weight body, and (C) an average diameter of 0.01
１０００1000 μm and average aspect ratio (length / length
An antifreeze-based automotive part material composed of a fibrous or needle-like filler composition having a diameter of 5 to 1000 exhibits high impact resistance, high heat resistance, high chemical resistance (coolant liquid resistance), and the like, When used in antifreeze-based automobile parts, especially antifreeze-resistant automobile parts used at high temperatures such as radiator tanks, polyamide resins are hydrolyzed by coolant over time and their physical properties are reduced. The antifreeze-resistant automobile part material has only an initial change at the time of immersion in the coolant, and hardly changes with time after immersion. The antifreeze-based automotive parts material of the present invention can be used not only in radiator tanks but also in antifreeze-based automotive parts such as water pump housings, water pump impellers, water valves, radiator pipes, heater tanks, etc. Plays a major role.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 7/14 C08K 7/14 C08L 21/00 C08L 21/00 23/16 23/16 F01P 11/00 F01P 11/00 Z // F28F 21/00 F28F 21/00

Claims (7)

[Claims] 1. An antifreeze-resistant automotive component material comprising a thermoplastic resin composition reinforced with a fibrous or acicular filler, wherein the composition comprises at least (A) a polyolefin resin and (B) a rubbery material. An antifreeze solution comprising a polymer and (C) a fibrous or acicular filler having an average diameter of 0.01 to 1000 m and an average aspect ratio (length / diameter) of 5 to 2500. Auto parts materials. 2. The ratio of each component of the thermoplastic resin composition is as follows:
(A) Polyolefin resin 90 to 20% by weight (B)
5 to 40% by weight of rubber-like polymer, (C) fibrous or acicular filler having an average diameter of 0.01 to 1000 μm and an average aspect ratio (length / diameter) of 5 to 2500 2. The antifreeze-resistant automotive part material according to claim 1, which is in weight%. 3. The antifreeze-resistant automobile part material according to claim 1, wherein the rubbery polymer as the component (B) is a partially or completely crosslinked rubbery polymer. 4. The antifreeze-resistant automobile part material according to claim 1, wherein the polyolefin resin as the component (A) is mainly a polypropylene resin. 5. The rubbery polymer as the component (B) is an ethylene / α-olefin copolymer rubber mainly composed of ethylene and an α-olefin having 3 to 20 carbon atoms.
5. An antifreeze-resistant automotive part material according to any one of claims 1 to 4. 6. The antifreeze-resistant automotive part material according to claim 1, wherein the filler as the component (C) is glass fiber and / or carbon fiber. 7. An antifreeze-resistant automobile part formed by molding the antifreeze-resistant automobile part material according to claim 1.