JPH08134319A - Part relating to antifreezing solution for cars - Google Patents

Abstract

PURPOSE: To provide parts relating to antifreezing solution for cars excellent in mechanical strength, heat-resistant toughness and dimensional stability as well as good resistance to antifreezing solution and creep resistance. CONSTITUTION: A resin composition comprising 100 pts.wt. of the resin components containing (a) 50-90wt.% of a modified polypropylene, (b) 10-50wt.% of a polyphenylene ether and (c) 15-200 pts.wt. of an inorganic filler is molded and cross-linked with water to give this part relating to antifreezing solution for cars.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition suitable for automotive antifreeze-related parts and an automotive antifreeze-related part obtained by molding and water-crosslinking the resin composition. More specifically, it relates to a resin composition having excellent mechanical strength, creep resistance, and excellent durability even in contact with an automobile antifreeze solution at high temperature, and a molded article thereof.

[0002]

2. Description of the Related Art In the field of automobiles, weight reduction, costume characteristics,
The use of resin for metal parts is progressing due to the advantages of improved productivity. Not only the outer panels such as bumpers and exterior parts, but also the metal parts inside the engine room are becoming resin. Typical parts in the engine room include antifreeze-related parts for automobiles. These are parts that come into contact with antifreeze liquids such as radiator tanks, water pump housings, and water valves for a long time at high temperatures. Conventionally, these have been mainly made of aluminum, but due to the above reasons, they have been made into resins, and at present, glass fiber reinforced polyamide resins are mainly used. This utilizes the excellent mechanical strength, heat resistance and oil resistance of the glass fiber reinforced polyamide resin. However, the polyamide resin has a drawback that its strength is lowered by being in contact with an antifreeze solution at a high temperature for a long time, and thus it cannot be said that it is necessarily the most suitable for a component which requires severe reliability. Further, polypropylene, which is widely used as an automobile part, has a great effect of reducing the weight and has no problem in strength reduction due to the antifreeze solution, but has a problem in practical use in terms of heat resistance and rigidity. Further, these cannot be said to have sufficient dimensional stability, and warpage occurs in the molded product, which causes a problem in flatness of the joint surface. Thus, no satisfactory material has been found as a material for the antifreeze-related parts to be mounted in the automobile engine room.

Therefore, the present inventors have found a composition comprising polypropylene, polyphenylene ether, and an inorganic filler as a material for antifreeze-related parts to be mounted in an automobile engine room. It has excellent mechanical strength, heat resistance rigidity, dimensional accuracy, and good antifreeze resistance, and the antifreeze related parts for automobiles obtained by molding this are enough to meet the recent demand for higher performance of resin parts for automobiles. It is compatible.

However, although this material contains polypropylene as the main component and is improved as compared with polypropylene alone, the deformation due to creep at high temperature was not always sufficient.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have excellent mechanical strength, heat resistance and dimensional stability, and maintain high mechanical strength even when they are in contact with an antifreeze solution at a high temperature for a long time.
It is an object of the present invention to provide a material suitable for antifreeze-related parts having excellent creep resistance and an antifreeze-related part formed by molding the material.

[0006]

That is, the present invention provides 100 parts by weight of a resin component consisting of 50 to 90% by weight of modified polypropylene obtained by grafting an ethylenically unsaturated silane compound onto polypropylene and 10 to 50% by weight of polyphenylene ether. And an automotive antifreeze-related component obtained by molding a water-crosslinking resin composition containing 15 to 200 parts by weight of an inorganic filler.

The present invention will be described in detail below. <Modified Polypropylene (a)> The modified polypropylene (a) obtained by grafting an ethylenically unsaturated silane compound onto the polypropylene used in the present invention means polypropylene having the general formula RSiR ′ in the presence of a radical generator.
_n Y _3-n (where R is an ethylenically unsaturated hydrocarbon or hydrocarbon oxy group, R'is an aliphatic saturated hydrocarbon group, Y
Represents a hydrolyzable organic group, and n represents 0, 1 or 2. ) Is an ethylenically unsaturated silane compound which is grafted by heating.

(1) Polypropylene The polypropylene used in the present invention is a polymer containing propylene as a main component, specifically, a propylene homopolymer, containing propylene as a main component, and ethylene, butene-1,
Hexene-1, heptene-1,4-methylpentene-
It is a copolymer with 1-, etc. α-olefins. The copolymer may be a random copolymer or a block copolymer, but a block copolymer is more preferable. Of these, crystalline polypropylene is preferable, and propylene homopolymer and propylene / ethylene block copolymer are particularly preferable.

The melt flow rate (JIS K-7210; 230 ° C., 2.16 kg load) of these polypropylenes is preferably 3.0 g / 10 minutes or less, more preferably 1.0 g / 10 minutes or less. If the melt flow rate exceeds 3.0 g / 10 minutes, the resulting modified polypropylene will have poor mechanical strength.

In the present invention, low density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-propylene rubber, ethylene-butene rubber, ethylene and vinyl acetate, (meth) acrylic acid, (meth) acrylic acid ester, anhydrous An ethylene resin such as a copolymer with maleic acid can also be used. The blending amount of these ethylene-based resins is preferably 30% by weight or less when the total amount of polypropylene and ethylene-based resin is 100% by weight.

[0011] (2) the ethylenically unsaturated silane compound in the ethylenically unsaturated silane compound present invention is a compound represented by the general formula RSiR _'n Y _{3- n.} Here, R represents an ethylenically unsaturated hydrocarbon group or a hydrocarbon oxy group, and specific examples thereof include vinyl, allyl, isopropenyl, butenyl, cyclohexenyl, γ- (meth) acryloyloxypropyl, and the like. Vinyl or γ
-(Meth) acryloyloxypropyl is preferred.
R'represents an aliphatic saturated hydrocarbon group, and specific examples thereof include methyl, ethyl, propyl, decyl and phenyl. Y represents a hydrolyzable organic group, and specific examples thereof include methoxy, ethoxy, formyloxy, acetoxy, propionyloxy, alkyl, arylamino and the like, with methoxy, ethoxy or acetoxy being preferred. n
Represents 0, 1 or 2, and is preferably 0. Examples of preferable ethylenically unsaturated silane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, γ-methacryloyloxypropyltrimethoxysilane and the like.

(3) Radical generator As the radical generator, any compound capable of generating a free radical site in the polypropylene under graft reaction conditions can be used. For example, Japanese Patent Publication No. 48-1711. The compounds described in etc. can be used. Typical radical generators include organic peroxides such as dicumyl peroxide, t-butyl-peroxyoctate and benzoyl peroxide, azo compounds such as azoisobutyronitrile and methylazoisobutyrate. Can be mentioned.

(4) Modification of polypropylene The amount of the ethylenically unsaturated silane compound used is 0.01 to 15 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of polypropylene. The amount used is 0.01 to 15 parts by weight, preferably 0.01 to
2 parts by weight.

It is also preferable that an antioxidant is present in the reaction system during the graft reaction in order to suppress deterioration of the resin due to molecular cleavage. As this antioxidant, those generally used as antioxidants for resins can be used. A typical example is 2,6-di-t-butyl-
4-methylphenol, 2,2'-methylene-bis- (4
-Methyl-6-t-butylphenol), 4,4'-butylidene-bis- (3-methyl-6-t-butylphenol), 4,4'-thiobis- (3-methyl-6-t-)
Butylphenol), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, tetrakis- [methylene-3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate] methane, 6- (3,5-di-t-butyl-4-hydroxyanilino) -2,4-bis-octylthio-1,3,5
-Triazine, tris- (3,5-di-t-butyl-4)
-Hydroxybenzyl) isocyanurate and the like having a radical chain inhibiting ability, and dilauryl thiodipropionate, distearyl thiodipropionate, trisnonylphenyl phosphite and the like having a peroxide decomposing ability and the like.

The amount of these antioxidants used is 0.005 to 10 parts by weight, preferably 0.01 to 5 parts by weight, based on 100 parts by weight of polypropylene, and the ratio of the amount to the amount of the radical generator used. It is desirable that the range is 0.05 to 50, and particularly 0.05 to 5. In the present invention, the graft reaction can be carried out in any state of melt, solution and individual phase and is not particularly limited.

In the present invention, the modified polypropylene alone or a mixture of the modified polypropylene and the unmodified polypropylene and / or the above-mentioned ethylene resin can be used. In this case, the modified polypropylene alone or a mixture thereof. The content of the silane compound unit therein is 0.001 to 10% by weight, preferably 0.01 to 10%
% By weight, particularly preferably 0.5-5% by weight,
The modified polypropylene alone or the above mixture has a melt flow rate of 0.5 to 200 g / 10 min, preferably 1 to
100 g / 10 min, particularly preferably 5 to 50 g / 10 min.

When the content of the silane compound unit is outside the above range, the mechanical strength is insufficient and the melt flow rate is 0.5.
If it is less than g / 10 minutes, the moldability is unsatisfactory, and 200 g /
If it exceeds 10 minutes, the mechanical strength will be insufficient. <Polyphenylene ether (b)> The polyphenylene ether (b) used in the present invention has the following general formula:

[0018]

Embedded image

(Wherein Q ¹ represents a halogen atom, a primary or secondary alkyl group, an aryl group, an aminoalkyl group, a hydrocarbonoxy group or a halohydrocarbonoxy group, and Q ² represents a hydrogen atom. , A halogen atom, a primary or secondary alkyl group, an aryl group, a haloalkyl group, a hydrocarbon oxy group or a halohydrocarbon oxy group, and m represents a number of 10 or more).

It is a homopolymer or a copolymer having a structure represented by Suitable examples of the primary alkyl group for Q ¹ and Q ² include methyl, ethyl, n-propyl, n-butyl,
n-amyl, isoamyl, 2-methylbutyl, n-hexyl, 2,3-dimethylbutyl, 2-, 3- or 4
-Methylpentyl or heptyl. Suitable examples of secondary alkyl groups include isopropyl, sec-butyl or 1
-Ethylpropyl. In many cases, Q ¹ is an alkyl group or a phenyl group, especially an alkyl group having 1 to 4 carbon atoms, and Q ² is a hydrogen atom.

Suitable homopolymers of polyphenylene ether are, for example, those composed of 2,6-dimethyl-1,4-phenylene ether units. Suitable copolymers include the above units and 2,3,6-trimethyl-1,
It is a random copolymer composed of a combination with a 4-phenylene ether unit. Many suitable homopolymers or random copolymers have been described in the patents and literature. Also suitable are polyphenylene ethers containing molecular moieties that improve properties such as, for example, molecular weight, melt viscosity and / or impact strength.

The polyphenylene ether used herein preferably has an intrinsic viscosity at 30 ° C. of 0.2 to 0.8 d1 / g measured in chloroform. The intrinsic viscosity is more preferably 0.2 to 0.7 d1 / g, and particularly preferably 0.25 to 0.6 d1 / g. If the intrinsic viscosity is less than 0.2 d1 / g, the impact resistance of the composition will be insufficient, and if it exceeds 0.8 d1 / g, the moldability will be unsatisfactory.

In the present invention, polystyrene, rubber-reinforced polystyrene, styrene-acrylonitrile copolymer,
It is also possible to use a styrene resin such as a styrene-acrylonitrile-butadiene copolymer. The compounding amount of these is 1 in total of polyphenylene ether and styrene resin.
When it is 00% by weight, it is preferably 30% by weight or less. <Inorganic Filler (c)> As the inorganic filler (c) used in the present invention, various known ones can be used. As an example, glass fibers, carbon fibers, potassium titanate whiskers, metal fibers, fibrous fillers such as wollastonite, talc, mica, plate-like fillers such as glass flakes, glass beads, spherical balls such as glass balloons. For example, a filler. It is also possible to use two or more of these in combination. Among these, the fibrous filler is most preferable from the viewpoint of the reinforcing effect, and the glass fiber is most preferable from the viewpoint of cost. When a fibrous filler is used, it is also preferable to use a plate-like filler together in order to suppress the warpage of the molded product due to anisotropy. It is more preferable that these inorganic fillers are treated with a silane-based or titanate-based surface treatment agent in order to improve the affinity with the resin component.

<Additional component> Further, other additional components can be added to the thermoplastic resin composition according to the present invention. For example, impact modifiers such as elastomers, antioxidants, weather resistance modifiers, nucleating agents, flame retardants, flame retardant aids such as anti-drip agents, additives such as lubricants and release agents, plasticizers, flow agents. A property improving agent, various colorants and their dispersants can be used as additional components.

Further, it is preferable to add a compatibilizer component in order to improve the compatibility between the polyphenylene ether and polypropylene. The compatibilizer used in the present invention may be any one as long as it improves the compatibility between the polyphenylene ether and polypropylene. Specific examples thereof include polyphenylene ether graft polypropylene, styrene graft polypropylene, partially hydrogenated alkenyl aromatic compound / conjugated diene block copolymer and the like. As such a compatibilizer component, the styrene-grafted polypropylene is commercially available from Mitsubishi Petrochemical Co., Ltd. under the trade name of "VMX", and the partially hydrogenated alkenyl aromatic compound / conjugated diene block copolymer is commercially available. As a product name from Shell Chemical Co., Ltd. under the product name of "Clayton G" and from Kuraray Co., Ltd.
It is sold by Asahi Kasei Kogyo Co., Ltd. under the product name "Tuftec" and can be easily obtained. The amount of these compatibilizers is preferably 0.1 to 40 parts by weight, more preferably 0.5 to 35 parts by weight, and particularly preferably 1 to 100 parts by weight based on 100 parts by weight of the total of polyphenylene ether and polypropylene. 30 parts by weight.

Further, in the present invention, the polyphenylene ether and the polypropylene are prepared by introducing into the polyphenylene ether a functional group having reactivity or affinity with the functional group in the modified polypropylene, or by adding a styrene resin having such a functional group. It is also possible to improve the compatibility. Specifically, a method of grafting a compound having an unsaturated group and the functional group onto polyphenylene ether, and a method of using a copolymer of styrene and a compound having the unsaturated group and the functional group can be used.

[Composition Ratio of Constituents] The composition ratio of the components (a) to (c) described above is as follows with respect to a total of 100 parts by weight of the components (a) and (b). Component (a): 50 to 90% by weight, preferably 50 to 85
%, Particularly preferably 55-80% by weight. Component (b): 10 to 50% by weight, preferably 15 to 50
%, Particularly preferably 20 to 45% by weight. Component (c): 15 to 200 parts by weight, preferably 25 to 1
50 parts by weight, particularly preferably 35 to 120 parts by weight.

If the amount of component (a) is less than 50% by weight, moldability is insufficient, and if it exceeds 90% by weight, heat resistance becomes unsatisfactory. If component (b) is less than 10% by weight, heat resistance is insufficient, and if it exceeds 50% by weight, moldability is unsatisfactory. Component (c) is 15
If it is less than 1 part by weight, mechanical strength and heat resistance are unsatisfactory, and 2
If it exceeds 100 parts by weight, moldability is insufficient.

[Manufacturing Method and Molding Method of Composition] Various known methods can be used to obtain the resin composition of the present invention, but melt kneading is the most general method. As the melt-kneader, a kneader generally used for thermoplastic resins can be applied. For example, a single-screw or multi-screw kneading extruder, a roll, a Banbury mixer, etc. may be used, and the kneading temperature is usually 180 ° C to 350 ° C.

The kneading method is such that all the components are blended and kneaded at the same time, the kneading is performed by using a blended product which is preliminarily kneaded, and some feed ports are provided in the middle of the extruder so that the respective components are sequentially added. Examples include the method of feeding. Specifically, using a modified polypropylene pre-kneaded in advance, a method of melt-kneading this and other components,
A method of melt-kneading all resin components at once, a method of melt-kneading polypropylene, an ethylenically unsaturated silane compound, and a radical generator in the front part of the extruder, and feeding other components from a feed port provided downstream. Can be taken.

The molded article of the present invention can be molded by molding methods generally used for thermoplastic resins, that is, injection molding, blow molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, and press molding. The resin composition of the present invention and its molded article are preferably exposed to a water atmosphere in the presence of a silanol condensation catalyst to carry out crosslinking (water crosslinking treatment).

As a silanol condensation catalyst, Japanese Examined Patent Publication No. 48
As disclosed in, for example, Japanese Patent Publication No. 1711,
Dibutyltin dilaurylate, dibutyltin diacetate,
There is dibutyltin dioctoate and the like, and it is used by blending it in the resin composition before molding, or by coating or impregnating it into a resin molded article after molding as a solution or dispersion. The amount of these silanol condensation catalysts used is
Generally, the amount is 0.001 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the modified polypropylene in the composition or the molded body.

In the water-crosslinking treatment, after molding the resin composition in a desired state, the molded article is subjected to water (liquid or vapor) at room temperature to about 200 ° C., usually room temperature to 100 ° C. for 10 seconds to 1 second.
The contact may be performed for about a week, usually for about 1 minute to 1 day. In the case of the antifreeze-related parts for automobiles of the present invention, even if the crosslinking treatment is not carried out in advance, it comes into contact with water at the time of use, so that the crosslinking treatment can be carried out.

The molded article of the present invention is used as an antifreeze-related component for automobiles. The antifreeze-related parts for automobiles referred to here are parts that come into contact with an antifreeze containing ethylene glycol as a main component. Specific examples include radiator tanks, water pump housings, water valves,
Examples include water impellers, radiator pipes, heater tanks, and the like.

[0035]

EXAMPLES The present invention will be described in more detail with reference to the following experimental examples. The evaluations in Examples and Comparative Examples were evaluated by the evaluation methods shown below. (1) Flexural modulus ISO R178-1974 Procedure 1
According to 2 (JISK-7203), it measured at 23 degreeC using the Instron tester.

(2) High temperature flexural modulus retention rate ISO R178-1974 Procedure 1
According to 2 (JISK-7203), measurement was performed at 80 ° C. using an Instron tester, and a retention rate for a bending elastic modulus at 23 ° C. was obtained. (3) Izod impact strength Measured at 23 ° C. according to JIS K-7110 notched Izod impact strength.

(4) Heat distortion temperature Using an HDT tester manufactured by Toyo Seiki Seisakusho, JIS
Evaluation was performed with a load of 18.6 kg according to K-7207. (5) Antifreeze resistance The tensile test piece (JIS tensile test piece No. 1 dumbbell) is immersed in a 50% aqueous solution of antifreeze solution and heated to 120 ° C for 10
The tensile strength after 00 hours was measured, and the retention rate for the unimmersed tensile strength was determined.

(6) Dimensional stability A 100 × 60 × 2 mm square plate having a film gate was injection molded, and the molding shrinkage in the machine direction (MD) and vertical direction (TD) of this molded product was measured. Difference (TD-M
D) was defined as dimensional stability. (7) Creep resistance JIS bending test piece (width 10 mm, thickness 4 mm, fulcrum spacing 6
4 mm) was continuously applied with a bending stress of 300 kg / cm ² at 80 ° C., and the time until breakage was measured.

<Reference Example> Melt flow rate is 0.3 g
/ 10 minutes 100 parts by weight of a propylene homopolymer, 5 parts by weight of vinyltrimethoxysilane, and 1 part by weight of benzoyl peroxide as a radical generator were sufficiently mixed with a super mixer. Next, this was melt-kneaded using a single-screw extruder set at 200 ° C. to produce a modified polypropylene grafted with a silane compound. The modified polypropylene had a melt flow rate of 16 g / 10 minutes and a silane compound content of 1.5% by weight.

<Example 1> 80 parts by weight of the modified propylene obtained in <Reference example> as the modified polypropylene (a) and poly 2,6-dimethyl-1,4-phenylene ether (Japan Polyether as the polyphenylene ether (b)) Intrinsic viscosity in chloroform at 30 ° C: 0.44d1 /
g) 20 parts by weight and 10 parts by weight of hydrogenated styrene-isoprene-styrene block copolymer (Kuraray Co., Ltd. trade name: Septon 2104) were sufficiently mixed and stirred with a super mixer. Then, using a TEX44 twin-screw extruder manufactured by Nippon Steel Co., Ltd., while melt-kneading at a preset temperature of 230 ° C. and a screw rotation speed of 250 rpm, an inorganic filler (c) was fed from a feed port provided in the middle of the extruder. As the above, glass fiber (made by Asahi Fiber Glass Co., Ltd., diameter: 10 μm) was fed so that the weight ratio of the resin component and the glass fiber was 110: 55, melt-kneaded to obtain a resin composition, and then pelletized.

A masterbatch in which 100 parts by weight of the propylene homopolymer described above and 1 part by weight of dibutyltin dilaurate were added to the above resin composition was added to the modified polypropylene in the resin composition at a weight ratio of 19: 1. Ratio, and using an in-line screw type injection molding machine (clamping force of 100T manufactured by Nippon Steel Co., Ltd.), a cylinder temperature of 260 ° C.,
Injection molding was performed at a mold cooling temperature of 80 ° C. to prepare a test piece.

In the injection molding, a vacuum dryer was used immediately before the injection molding under the conditions of 0.1 mmHg and 23 ° C.
It was dried for 8 hours. Then, the obtained molded product is treated with 100
After immersing in hot water of ℃ for 24 hours to perform cross-linking treatment,
An evaluation test was conducted and the results are shown in Table-1. <Examples 2 and 3 and Comparative Examples 1 and 2> Melt kneading, molding, water-crosslinking treatment and evaluation were carried out in the same manner as in Example 1 except that the composition ratio of each component was changed to the ratio shown in Table 1. The results are shown in Table-1.
It was shown to.

Example 4 The resin components were sufficiently mixed and stirred in a super mixer at the ratios shown in Table 1. Then, using a TEX44 twin-screw extruder manufactured by Nippon Steel Co., Ltd., while melt-kneading at a preset temperature of 230 ° C. and a screw rotation speed of 250 rpm, from a feed port provided in the middle of the extruder,
As the inorganic filler (c), glass fiber (made by Asahi Fiber Glass Co., Ltd., diameter: 10 μm), mica (made by Kuraray Co., Ltd.) is used as resin component and the ratio of glass fiber and mica is 110: 35: 20.
The composition was fed, melt-kneaded to obtain a composition, pelletized, molded, water-crosslinked and evaluated in the same manner as in Example 1, and the results are shown in Table 1.

<Comparative Example 3> The modified polypropylene used in Example 1 was replaced with a propylene homopolymer (trade name: Mitsubishi Polypro MA2A manufactured by Mitsubishi Yuka Co., Ltd., melt flow rate: 2).
5 g / 10 min) except that the melt kneading, molding, water-crosslinking treatment and evaluation were carried out in the same manner as in Example 1
Shown in 1.

<Comparative Example 4> Melt kneading, molding in the same manner as in Example 1 except that the catalyst masterbatch was not blended during molding and the water-crosslinking treatment of the molded product was not carried out.
The evaluation was performed and the results are shown in Table 1.

[0046]

[Table 1]

[0047]

EFFECT OF THE INVENTION The resin composition for antifreeze-related parts of the present invention has excellent characteristics such as high mechanical strength, heat resistance and dimensional stability, and good antifreeze resistance and creep resistance. The antifreeze-related parts for automobiles obtained by molding and water-crosslinking process sufficiently meet the recent demand for higher performance of resin parts for automobiles.

Claims (1)

[Claims] 1. 100 parts by weight of a resin component consisting of (a) 50 to 90% by weight of a modified polypropylene obtained by grafting an ethylenically unsaturated silane compound on polypropylene, and (b) 10 to 50% by weight of polyphenylene ether. ) An antifreeze-related component for an automobile obtained by molding a resin composition containing 15 to 200 parts by weight of an inorganic filler and subjecting it to a water crosslinking treatment.