JPH0782331A - Production of thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition improved in compatibility between the constituent polyamide resin and the constituent propylene polymer, having excellent wear resistance, electrical properties, heat distortion resistance and mechanical strengths inherent in the polyamide resin, and having low hygroscopicity inherent in the propylene polymer and having high impact resistance. CONSTITUTION:An aromatic vinyl monomer and a free radical initiator are subjected to melt kneading and polymerization reaction in the presence of a resin composition comprising a propylene polymer and a polyamide resin is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple thermoplastic resin composition comprising a propylene polymer and a polyamide resin, which has excellent impact resistance, rigidity, heat distortion resistance and low water absorption. Manufacturing method.

[0002]

2. Description of the Related Art Polyamide resin is used for abrasion resistance, electrical characteristics,
Since it is excellent in heat distortion resistance and mechanical strength, it is widely used as an engineering resin in various mechanical parts materials, but it has drawbacks such as insufficient impact resistance and high water absorption.

In particular, the deterioration of physical properties due to water absorption is a problem, and when molding the water-absorbed polyamide resin, air bubbles enter and molding is unfavorable, which is not preferable. Further, the absorption of water causes problems such as reduction in mechanical strength and dimensional change of the molded product. Occurs.

Since the polyamide resin has such drawbacks, its application as an engineering resin is limited, and it is often impossible to take advantage of the excellent characteristics inherent to the polyamide resin.

On the other hand, propylene-based resin is a resin having a low cost, a low specific gravity, almost no water absorption and an excellent balance of physical properties, but it has drawbacks such as insufficient mechanical strength, especially physical properties at high temperature. is there.

Accordingly, attempts have been made to blend these resins in order to improve the respective drawbacks of polyamide resins and propylene-based polymers.

However, even if the polyamide resin and the propylene-based polymer are blended by simply melt-kneading the mixture using an extruder or the like, the compatibility between the two is poor, resulting in delamination and poor mechanical strength. I can only get it. That is, since the propylene-based polymer is a non-polar resin and does not have an active functional group capable of reacting with the polyamide resin, it is not compatible with the polyamide resin, which is a polar resin, as it is.

To improve the compatibility, for example, a propylene polymer obtained by modifying a part of a propylene polymer with a carboxylic acid or an anhydride thereof is used (Japanese Patent Publication No. 45-30943, Kaisho 60-
(118735 gazette) The method of improving the compatibility with a polyamide resin is performed. However, although the compatibility is improved by the inclusion of the acid-modified propylene-based polymer described above, the propylene-based polymer is a radical-disintegrating polymer unlike other polyolefins. Or, when it is melt-kneaded with a polyamide resin by this method due to a decomposition reaction of a propylene-based polymer, or an adverse effect of an unreacted residual monomer when modified with an anhydride thereof, an effect of improving mechanical properties, a molded product. The appearance was not always satisfactory.

Further, in producing a composition of a polyamide resin and a polyolefin, a thermoplastic resin composition comprising a radical initiator and a polymerizable compound having a glycidyloxy group in order to improve the compatibility of the two. A manufacturing method has also been proposed (JP-A-5-39330). However, when a propylene-based polymer is used as the polyolefin, the propylene-based polymer itself is a radical-disintegrating polymer as described above. Therefore, in order to react the above-mentioned polymerizable compound, simply using a radical initiator results in Decomposition reaction occurs simultaneously, and high mechanical properties cannot be obtained. When the amount of the radical initiator added is reduced in order to suppress the decomposition, not only the reaction rate of the polymerizable compound decreases and the amount of unreacted monomer increases, but also the amount of the functional group introduced can be increased. Therefore, there is a problem that high compatibility or a satisfactory effect of improving physical properties cannot be obtained.

[0010]

DISCLOSURE OF THE INVENTION The present invention solves the problems of these conventional compositions and further improves the compatibility of the polyamide resin and the propylene-based polymer, resulting in excellent abrasion resistance of the polyamide resin. To provide a method for producing a thermoplastic resin, which is obtained by a simpler method with a resin composition having the following properties: electrical properties, electrical properties, heat distortion resistance and mechanical strength, and low water absorption properties of a propylene-based polymer. To aim.

[0011]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned drawbacks of the conventional method, the present inventors have found that in the presence of a resin composition comprising a propylene-based polymer and a polyamide resin, a fragrance is obtained. Group vinyl monomer and radical initiator,
The inventors have found that the above objects can be achieved by carrying out a melt-kneading polymerization reaction, and completed the present invention. The aromatic vinyl monomer here is preferably a monomer mixture obtained by combining an aromatic vinyl monomer and a polar functional group-containing vinyl monomer, and further, a polar functional group-containing vinyl monomer. The body is preferably an epoxy group-containing vinyl monomer or a carboxyl group-containing vinyl monomer.

The present invention will be described in detail below.

(Constitution) The propylene-based polymer of the present invention is
A propylene homopolymer and a copolymer containing propylene as a main component and another olefin or an ethylenic vinyl monomer (each of which is a copolymer containing propylene at 75% by weight or more), and specifically, isotactic polypropylene, Examples include propylene-ethylene copolymer and propylene-butene copolymer. These propylene-based polymers can be used alone or in combination. Further, other polymers can be used as long as the properties of the propylene polymer are not impaired.

Polyamide resin means acid amide (--CON
A polymer compound having H-) as a repeating unit includes, for example, a compound obtained by ring-opening polymerization of a lactam, a compound obtained by polycondensation of a diamine and a dibasic acid, and a compound obtained by polycondensation of an aminocarboxylic acid depending on the polymerization mode. These have the common name of nylon, such as nylon 6, nylon 12,
Nylon 9, Nylon 11, Nylon 66, Nylon 6
10 and the like, among them, nylon 6,
Nylon 66 is preferred. The molecular weight of the polyamide resin is not particularly limited, but usually the relative viscosity (η _rel ) is 0.5.
As described above, those corresponding to 2.0 or more are preferably used.

The propylene polymer and the polyamide resin of the present invention may be blended in any proportion depending on the intended use. Preferably 1 to 99 parts: 99 to 1 part. The aromatic vinyl monomer is a combination mixture of an aromatic vinyl monomer and a polar functional group-containing vinyl monomer, and specific examples of the aromatic vinyl monomer here include styrene, Methyl styrene, vinyl toluene, vinyl xylene, ethyl vinyl benzene, isopropyl styrene,
Chlorostyrene, dichlorostyrene, bromostyrene, etc. are mentioned, and these are used individually or in mixture.
The polar functional group-containing vinyl monomer, epoxy group-containing vinyl monomer, carboxylic acid group-containing vinyl monomer,
Examples thereof include a hydroxyl group-containing vinyl monomer, an oxazoline group-containing vinyl monomer, and an amino group-containing vinyl monomer. Preferably, it is an epoxy group-containing vinyl monomer or a carboxyl group-containing vinyl monomer.

More specifically, the epoxy group-containing vinyl monomer is, for example, glycidyl methacrylate,
Glycidyl acrylate, allyl glycidyl ether,
Methacrylglycidyl ether and the like can be mentioned, and these can be used alone or in combination. Glycidyl methacrylate is particularly preferable. The carboxylic acid group-containing vinyl monomer includes, for example, acrylic acid, methacrylic acid, maleic anhydride, maleic acid and the like, and these are used alone or as a mixture thereof.

Examples of the hydroxyl group-containing vinyl monomer include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and 2
-Hydroxybutyl methacrylate and the like can be used, and these can be used alone or in combination. Examples of vinyl monomers containing an oxazoline group are 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-
Examples include isopropenyl-2-oxazoline and 2-isopropenyl-4-oxazoline.

The amount of the aromatic vinyl monomer added is 50% by weight or less, preferably 1 to 35% by weight, based on the propylene polymer to be blended. The aromatic vinyl monomer is used in order to prevent the propylene-based polymer from having a low molecular weight and to improve the compatibility with the polyamide resin, at least the same amount as the addition amount of the polar functional group-containing vinyl monomer, preferably 1 ~
It is preferable to add 5 times the amount.

The aromatic vinyl monomer may be mixed with the resin mixture in advance and then fed to the extruder.
It may be supplied to the molten resin mixture using a liquid feeder.

The amount of the polar functional group-containing vinyl monomer added is 10% by weight or less, preferably 0.1 to 5% by weight, based on the propylene polymer to be blended. If it exceeds 10% by weight, the unreacted monomer increases, which may adversely affect the adhesiveness and mechanical properties of the composition, which is not preferable.

The radical initiator preferably has a decomposition temperature of 130 to 250 ° C. for obtaining a half-life of 1 minute in order to carry out the polymerization at the melt-kneading temperature necessary for carrying out the present reaction. Specific examples include t-butyl peroctate, bis (t-butyl peroxy) trimethylcyclohexane, cyclohexanone peroxide, benzoyl peroxide, dicumyl peroxide, t-butyl perbenzoate, dimethyl di (t-butyl peroxide). Oxy) hexane, dimethyldi (t-butylperoxy) hexyne, etc. may be mentioned. The radical initiator is usually 0.1 per 100 parts by weight of the total vinyl monomer added.
It is good to add in a ratio of 10 to 10 parts by weight, preferably 1 to 5 parts by weight. Further, it is preferable to add a powder propylene polymer impregnated with a radical initiator in advance as a masterbatch.

The radical initiator may be added by dissolving it in the aromatic vinyl monomer in advance, or by adding it with a liquid feeder at the time of melting, or by adding a propylene polymer or the like. The powder material may be impregnated and mixed in advance and used as a masterbatch. The stabilizer is preferably mixed in advance with the propylene polymer by using a Henschel mixer or the like.

Unlike other polyolefins such as polyethylene, the propylene-based polymer is a radical-disintegrating polymer, and therefore it is preferable to add a stabilizer as another additive. However, it is necessary to consider the type and addition amount so as not to hinder the polymerization of the aromatic vinyl monomer. For example, pentaerythrityl-tetrakis ((di-t-butyl-hydroxyphenyl) propionate), ocdecyl (di-t-butyl-hydroxyphenyl) propionate, thiobis (methyl t-butylphenol), trimethyl-tris (di-t-butyl). Hydroxybenzyl)
Hindered phenol-based stabilizers such as benzene, phosphorus-based stabilizers such as tetrakis (di-t-butylphenyl) biphenylene phosphite and tris (di-t-butylphenyl) phosphite, metal soaps such as zinc stearate and calcium stearate. , Magnesium oxide, hydrotalcite and other antacid adsorbents. The amount of the stabilizer used is usually 0.01 to 1 part by weight, preferably 0.05 to 0.5 part by weight, based on 100 parts by weight of the propylene polymer.

The reaction according to the present invention can be carried out using a closed container such as a Banbury mixer or a continuous kneader such as an extruder. Of these, the extruder is preferable when considering industrial production such as granulation. Further, a twin-screw extruder is more preferable in terms of supply of reactants, high resin kneading property, control of polymerization time, and the like.

As an actual method for producing a thermoplastic resin composition, a powder or pellet-shaped resin mixture of a propylene polymer and a polyamide resin, an aromatic vinyl monomer, and a radical initiator are previously prepared. Or impregnate or mix
It is supplied to the molten resin composition with a liquid feeder, melt-kneaded at 150 to 280 ° C. under pressure in an extruder or the like, melt-kneading polymerization reaction of an aromatic vinyl monomer, and then discharged from a die Cool and pellet using a pelletizer.

As described above, since the propylene-based polymer is a radical-disintegrating polymer unlike the ethylene-based polymer, the molecular weight is apt to decrease due to the cleavage of the main chain when simply melt-heated. Therefore, even if only the polar functional group-containing vinyl monomer is melt-kneaded in the presence of the radical initiator, the physical properties are deteriorated due to the decrease in the molecular weight. However, according to the melt-kneading reaction method of the present invention, by using the aromatic vinyl monomer in combination, the polar functional group-containing vinyl monomer can be efficiently reacted, and the propylene-based polymer and the polyamide resin A thermoplastic resin composition having an improved compatibility of
It can be manufactured by a simpler method.

In addition to these essential components, additional components can be added to the composition obtained in the present invention within a range that does not impair the effects of the invention. Examples of the additional component include other thermoplastic resins, rubbers, inorganic fillers, pigments, various stabilizers (antioxidants, light stabilizers, antistatic agents, antiblocking agents, lubricants) and the like.

In the present invention, the propylene polymer, the polyamide resin, the aromatic vinyl monomer and the radical initiator are dry blended with a Henschel mixer, a V blender, a ribbon blender, a tumbler blender, etc. A melt-kneading polymerization reaction may be carried out, or the above-mentioned aromatic vinyl monomer and radical initiator may be reacted with a melt mixture of a propylene polymer and a polyamide resin. In particular, the present method can be applied to a recycling application such as reuse of waste materials produced from a laminated sheet of a propylene-based polymer and a polyamide resin, and is very effective.

In this way, the production method of the present invention provides a thermoplastic resin composition excellent in well-balanced low water absorption, impact resistance, heat resistance, rigidity and surface property by a simpler method. be able to.

[0030]

EXAMPLES Next, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following, all parts and% are based on weight unless otherwise specified.

The methods for testing the physical properties of the composition are as follows. Melt index (g / 10 minutes): JIS K721
0 (2.16 Kg, 230 ° C.) Delamination: The molding surface was wiped with toluene and the presence or absence of delamination was visually judged.

Thermal Deformability (° C): Measurement JIS K7207
(Load 4.6 Kgf / cm ² ) Bending elastic modulus (kg / cm ² ): According to JIS K7203 measurement, during drying and water absorption (23 ° C., 24 hours after immersion in water, sample measurement) Impact strength (kg cm / cm ² ). : Measurement ASTM D256 Water absorption rate (%): Calculated by the following formula after using an injection test piece (104 * 50 * 2mm) for 24 hours at 23 ° C.

Example 1 A 30 mm twin-screw extruder manufactured by Brabender (Germany) was set to a barrel temperature of 230 ° C. (however, a feeder section of 180 ° C.) and a die temperature of 240 ° C. Irganox 1010 on 100 parts of powdered homopolypropylene (Hipol B200P, manufactured by Mitsui Petrochemical Co., Ltd.)
(Stabilizer manufactured by Ciba-Gaiki) 0.05 parts, phosphite 168 (stabilized by Ciba-Gaiki) 0.05 parts, and calcium stearate (stabilizer) 0.1 parts in advance, and the stabilizer is mixed. It was a thing. To 300 parts of the powdered homopolypropylene (Hypol B200P, manufactured by Mitsui Petrochemical Co., Ltd.) containing the above stabilizer, 700 parts of nylon-6 (nylon MC112 manufactured by Kanebo Co., Ltd.) was further mixed, and styrene 1 was added.
5 parts, 9 parts of glycidyl methacrylate and 2 parts of perhexin
5B [Dimethyldi (t-butylperoxy) hexine
0.7 parts by Nippon Oil & Fats Co., Ltd. was mixed to prepare a dry blend. The obtained dry blend was supplied to an extruder and melt-kneaded at 15 rpm to perform a melt-kneading reaction to obtain product pellets. The obtained pellets are manufactured by Toshiba IS50
Using an AM injection molding machine, test pieces were prepared under the condition of a resin temperature of 260 ° C., and various physical properties were evaluated. The results are shown in Table 1.

Example 2 A thermoplastic resin composition was produced by using the same amount of methacrylic acid instead of using 9 parts of glycidyl methacrylate in the production of Example 1, and various physical properties were obtained in the same manner as in Example 1. Was evaluated. The results are shown in Table 1.

Example 3 In the production of Example 1, 500 parts of homopolypropylene (Hypol B200P, manufactured by Mitsui Petrochemical Co., Ltd.), 500 parts of nylon-6 (nylon MC112 manufactured by Kanebo Co., Ltd.), 25 parts of styrene, 15 parts of glycidyl methacrylate are used. A thermoplastic resin composition was produced under the same conditions as in Example 1 except that 1.2 parts of Perhexin 25B [dimethyldi (t-butylperoxy) hexine manufactured by NOF CORPORATION] was used in Example 1. Various physical properties were evaluated in the same manner as. The results are shown in Table 1.

Example 4 In the production of Example 1, instead of using 300 parts of homopolypropylene (Hipol B200P, manufactured by Mitsui Petrochemical Co., Ltd.), the same amount of block polypropylene (Highpol J340P, manufactured by Mitsui Petrochemical Co., Ltd.) was used. Example 1 to produce a thermoplastic resin composition.
Various physical properties were evaluated in the same manner as. The results are shown in Table 1.

[0037]

[Table 1]

Comparative Example 1 In the production of Example 1, only 300 parts of homopolypropylene (Hypol B200P, manufactured by Mitsui Petrochemical Co., Ltd.) and 700 parts of nylon-6 (nylon MC112, manufactured by Kanebo Co., Ltd.) were mixed, melt-kneaded and heated. A plastic resin composition was produced, and various physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 2. The obtained molded product was delaminated and a uniform molded product could not be obtained.

Comparative Example 2 Instead of using homopolypropylene (Hypol B200P, manufactured by Mitsui Petrochemical Co., Ltd.) in the preparation of Comparative Example 1, the same amount of block polypropylene (Highpol J340, manufactured by Mitsui Petrochemical Co., Ltd.) was used. Except for this, in the same manner as in Example 1, melt kneading was performed to produce a thermoplastic resin composition, and various physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 2. The molded product obtained in the same manner as in Comparative Example 1 was delaminated, and a uniform molded product could not be obtained.

Example 3 In the production of Example 1, instead of using 15 parts of styrene and 9 parts of glycidyl methacrylate, only 9 parts of glycidyl methacrylate was used.
Accordingly, a thermoplastic resin composition was produced under the same conditions as in Example 1, except that 0.27 part of the radical initiator perhexin 25B [dimethyldi (t-butylperoxy) hexine manufactured by NOF CORPORATION] was used, Various physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 2. The obtained molded product was partly delaminated, and the melt index of the obtained pellet was a high value, and the monomer odor was strong.

(Comparative Examples 4 and 5) Polyamide resin (Nylon MC112 manufactured by Kanebo Co., Ltd.) and polypropylene resin (Hypol B200 manufactured by Mitsui Petrochemical Co., Ltd.) for comparison of physical properties.
Was used alone to produce a molded product, and various physical properties were evaluated in the same manner as in Example 1.

[0042]

[Table 2]

[0043]

[Effect of the Invention] In the presence of a resin composition consisting of a propylene polymer and a polyamide resin, an aromatic vinyl monomer and a radical initiator are subjected to a melt-kneading polymerization reaction,
By improving the compatibility of polyamide resin and propylene-based polymer, the excellent abrasion resistance, electrical properties, heat distortion resistance and mechanical strength of polyamide resin, and low water absorption properties of propylene-based polymer can be obtained. It is possible to provide a method for producing a thermoplastic resin composition, which can obtain a resin composition having a high impact resistance in a combined manner by a simpler method. In particular, it has a great utility value as a molding material, a packaging container material, a housing material for electric parts and the like.

Claims (4)

[Claims] 1. A thermoplastic resin composition characterized by performing a melt-kneading polymerization reaction of an aromatic vinyl monomer and a radical initiator in the presence of a resin composition consisting of a propylene polymer and a polyamide resin. Manufacturing method. 2. The heat according to claim 1, wherein the aromatic vinyl monomer is a monomer mixture formed by combining an aromatic vinyl monomer and a polar functional group-containing vinyl monomer. A method for producing a plastic resin composition. 3. The method for producing a thermoplastic resin composition according to claim 2, wherein the polar functional group-containing vinyl monomer is an epoxy group-containing vinyl monomer or a carboxyl group-containing vinyl monomer. . 4. The method for producing a thermoplastic resin composition according to claim 1, wherein the aromatic vinyl monomer is styrene.