JPH05186648A - Production of resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, having a low water absorbency, excellent in adhesion, moldability and coating properties and suitable as members, etc., such as automotive exterior trims and exterior sheets by melt kneading a modified PP-based resin with a polyamide resin and an amino group- containing compound. CONSTITUTION:The objective composition is obtained by melt kneading (A) (i) a modified polyolefinic resin such as a graft-modified polyolefinic resin graft modified with acrylic acid, etc., and (ii) a modified PP-based resin composed of a PP-based resin, (B) a polyamide resin such as 6 mylon, (C) a compound selected from one or more of amines, diamines and diaminecarbamates containing one or more amino groups in one molecule. Furthermore, the blending ratio of the components (A) to (C) is preferably 50-70wt.% component (A), 30-50wt.% component (B) and the component (C) in an amount of 0.1-2 pts.wt. wt. based on 100 pts.wt. total amount of the components (A) and (B).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a resin composition containing polyolefin and polyamide as main components. More specifically, it is a composition containing a polyolefin and a polyamide as main components, and the molded article of the composition has a specific surface state, so that urethane-based paints, etc. do not require special surface treatment such as primer undercoating. The present invention relates to a method for producing a resin composition having excellent adhesiveness with.

The composition obtained by this production method is
It is useful as a member that requires paintability in the field of automobiles, such as a wheel cover, bumper, and air spoiler.

[0003]

2. Description of the Related Art Polypropylene resins are not only excellent in moldability but also have good mechanical properties, heat resistance, solvent resistance, oil resistance, chemical resistance, etc. It is manufactured and used in various fields as industrial parts such as automobiles, electric and electronic appliances, and daily necessities. However, polypropylene resin does not have a polar group in the molecule,
In addition, it has high crystallinity and is extremely chemically inactive, which causes a problem in adhesion with urethane coatings and the like. As an example of a method for solving this problem, as a method for improving adhesion with a coating material such as a bumper or the like, which is used for a polypropylene resin molded article, a method for improving adhesion is generally used: halogenated organic materials such as trichlene, perchlorethylene, and pentachloroethylene. The adhesiveness of the paint is improved by making the surface of the molded product uneven with a solvent and undercoating a primer such as chlorinated polyolefin. However, even with this method, the adhesiveness of the paint is not sufficient, and the problem of solvent resistance such as gasohol has not been sufficiently solved. Moreover, since this method increases the number of processes and facilities, it is not considered to be a preferable method in terms of production efficiency and cost. Further, from the viewpoint of protection of the global environment, which is currently a big problem in industry, this method using a halide is not preferable. Therefore, it can be said that dehalogenation in the coating process of the molded product of the propylene-based resin composition is a problem to be achieved immediately.

In order to solve this problem, various attempts have been made to modify the polypropylene resin. These attempts can be roughly classified into the following. (A) Modification of the surface of the molded article by a method such as plasma treatment (b) Improvement of solvent permeability by addition of an amorphous resin such as styrene resin (c) Polypropylene of polar monomer such as unsaturated carboxylic acid (D) Improving the anchor effect of the paint by roughening the surface of the molded product by adding an inorganic filler or the like. However, these attempts also lead to surface treatment with a halogenated organic solvent or primer. Undercoating process, or even if both processes can be omitted, the paint adhesion is not sufficient, or even if the paint adhesion is sufficient, the chemical resistance and gasohol resistance are poor. There was a problem, and I couldn't help solving the problem.

On the other hand, polyamide resin is widely used as an engineering resin in the fields of automobile parts and electric / electronic parts, which is characterized by heat resistance, rigidity, strength and oil resistance. However, the polyamide resin has a high water absorption rate due to an amide bond in the main chain, and therefore, dimensional changes and mechanical properties change greatly during drying and water absorption, which poses a problem when the polyamide resin is used as a structural material. Furthermore, further improvement in molding processability, impact resistance, and chemical resistance is desired. There are also problems that the specific gravity is large and the price is high as compared with polyolefin.

[0006]

From this point of view, coating with a composition comprising a modified polyolefin resin, a polypropylene resin and a polyamide resin, and a composition obtained by mixing the composition with a fibrous reinforcing material and / or an inorganic filler. A method for improving the property is proposed in Japanese Patent Laid-Open Nos. 3-146551, 3-146552 and 3-146554. The greatest feature of the compositions disclosed in these publications is that the relationship of a specific melt viscosity ratio between the polypropylene resin and the polyamide resin is defined, and the compounding amount of the polyamide resin is 40 to 80% by weight. The point is that the composition is defined in a region where the blending amount of the polyamide resin is relatively large, such as%.

In the case of the compositions disclosed in these publications, if the blending amount of the polyamide resin is selected in the range of more than 50% by weight in order to secure the coatability, the water absorption rate becomes high, and the water absorption rate during drying and water absorption is high. The difference in physical properties becomes a problem. On the other hand,
When the content of the polyamide resin is 50% by weight or less, the water absorption certainly lowers, but the composition obtained is inferior in fluidity, and the dispersibility of the dispersion layer is insufficient, so that the composition is structurally unstable. However, a composition that solves the problem has not been obtained yet.

An object of the present invention is to provide a molded product having a low water absorption rate, which is excellent in moldability, and which gives a molded product having excellent adhesion to a urethane-based paint or the like without any special treatment such as primer undercoating. It is to provide a method for producing a composition.

[0009]

Means for Solving the Problems As a result of repeated research to solve this problem, the present inventor has melted a specific compound in a modified polypropylene resin and a polyamide resin composed of a modified polyolefin resin and a polypropylene resin. The problem was solved by the kneading manufacturing method.

That is, according to the present invention, (A) (a) a modified polyolefin resin, (b) a modified polypropylene resin composed of a polypropylene resin, (B) a polyamide resin and (C) an amino group, one in each molecule. The present invention relates to a method for producing a resin composition, which comprises melt-kneading at least one compound selected from the compounds contained above.

The composition comprising the above components (A) and (B) is already known as mentioned above. The feature of the present invention resides in that the composition or mixture comprising the components (A) and (B) is mixed and added with the component (C) and melt-kneaded. When the respective components (A) and (B) are melt-kneaded, both components can be in a continuous phase depending on the relationship between the volume ratio of the components (A) and (B) and the melt viscosity ratio. Moldability does not improve paintability sufficiently. The desired object can be achieved only by the composition obtained by the manufacturing method in which the component (C) is added during or during the kneading of the components (A) and (B).

The (A) modified polypropylene resin used in the present invention comprises (a) modified polyolefin resin and (b) polypropylene resin. As the component (A), the components (a) and (b) may be melt-kneaded in advance, or may be simply mixed by a Henschel mixer or the like. The modified polyolefin resin (a) used in the present invention can be roughly classified into the following two types. (1) Graft modified polyolefin In the presence of a radical generator, α, β-
Graft-modified polyolefin grafted with an unsaturated carboxylic acid or its derivative (2) Multi-component modified polyolefin Obtained by copolymerizing an olefin monomer with an α, β-unsaturated carboxylic acid or its derivative, and a methacrylic acid ester or an acrylic acid ester. The modified polyolefin used in the present invention is (1) or (1) and (2) in combination.

Of these, with respect to the graft-modified polyolefin of (1), the modified polyolefin is
Ethylene, propylene, butene-1, pentene-1, 4
-Homopolymers and copolymers of C2-C20 α-olefins such as methylpentene-1 and copolymers of these α-olefins with olefin derivatives such as vinyl acetate and acrylic acid esters, and these A mixture can be given.

As the α, β-unsaturated carboxylic acid or its derivative used for the graft modification, acrylic acid,
Maleic acid, fumaric acid, itaconic acid, citraconic acid,
Examples thereof include unsaturated carboxylic acids such as crotonic acid and isocrotonic acid, and acid anhydrides and esters of these unsaturated carboxylic acids. Of these, acrylic acid, maleic acid, and maleic anhydride are preferable. In addition, these may be used individually or in mixture of 2 or more types.

As the radical generator used for the graft modification, dicumyl peroxide, benzoyl peroxide, di-t-butyl peroxide, 2,5-
Organic peroxides such as dimethyl-2,5-di (t-butylperoxy) hexane and 2,5-dimethyl-2,5-di (t-butylperoxy) hexene-3 are preferably used.

The method for producing the graft-modified polyolefin of (1) is not particularly limited and can be produced by a known method. As a preferable production method, an extruder, a Banbury mixer, a kneader or the like is used and a polyolefin is obtained. The method of producing by melt-kneading the α, β-unsaturated carboxylic acid or its derivative and the radical generator can be mentioned. The compounding amount of each compound used at this time is not particularly limited and may be selected according to the situation, but it is preferable to select the compounding amount in a range in which the graft addition amount is 0.01 to 10% by weight. It is preferable to select the blending amount within the range in which the graft addition amount is 0.1 to 5% by weight. If the graft addition amount is less than 0.01% by weight, it is not possible to stably produce a composition of polypropylene resin and polyamide resin having greatly different polarities. Moreover, the graft addition amount is 10% by weight.
If it exceeds, the effect is little corresponding to the graft addition amount, and rather the fluidity of the obtained composition may be impaired.

In the multi-component modified polyolefin (2), various olefin monomers can be used, but ethylene, propylene, butene-1,4-methylpentene-1 and the like are preferable. However, ethylene is more preferable. Further, as the α, β-unsaturated carboxylic acid or its derivative, the same ones as described above are used.

As a method for producing the multi-component modified polyolefin, a usual polymerization method can be used. The compounding amount of each compound used in this case is not particularly limited and may be selected depending on the situation, but the content of the α, β-unsaturated carboxylic acid or its derivative is 0. 0 for the same reason as described above. 0
It is preferable to select the compounding amount in the range of 1 to 10% by weight, and it is more preferable to select the compounding amount in the range of 0.1 to 5% by weight of the derivative content.

The polypropylene resin (b) is a propylene homopolymer and / or a propylene copolymer. The propylene copolymer used here is propylene and ethylene and / or butene-1, pentene-1. , 4-methylpentene-1 and the like, and block copolymers and random copolymers with α-olefins having 4 to 20 carbon atoms. As the component (b), one type of propylene homopolymer or propylene copolymer may be used, or two or more types may be used in combination.

The modified polypropylene resin (A) is
(A) Modified polyolefin resin 10 to 50% by weight and (b) Polypropylene resin 90 to 50% by weight. When the amount of the modified polyolefin resin (a) is less than 10% by weight, the miscibility with the (B) polyamide resin cannot be sufficiently improved, and when it exceeds 50% by weight.
When the reaction with the (B) polyamide resin proceeds excessively, the composition becomes inferior in fluidity, and the problem cannot be solved.

Examples of the (B) polyamide resin used in the present invention include polyamides obtained by polycondensation of lactams having three or more membered rings, polymerizable ω-amino acids, dibasic acids and diamines. Specifically, ε-caprolactam, aminocaproic acid, enantolactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid nadnojugotai, hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, metaxylylenediene. Examples thereof include polymers obtained by polycondensing diamines such as amines with dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid and dodecane dibasic acid, or copolymers thereof.

Specific examples include polyamide 6, polyamide 6,6, polyamide 6,10, polyamide 11, polyamide 12, aliphatic polyamides such as polyamide 6,12, polyhexamethylenediamine terephthalamide,
Aromatic polyamides such as polyhexamethylenediamine isophthalamide and xylene group-containing polyamides can be mentioned, and they can be used as a mixture or a copolymer of two or more kinds thereof.

The component (C) used in the present invention is at least one compound selected from compounds containing at least one amino group in one molecule. Examples of the compound containing one or more amino groups in one molecule include amine-containing compounds such as amines, diamines, diamine carbamates and melamine. Specifically, amines such as methylamine, ethylamine, ethanolamine and propylamine, diamines such as trimethylenediamine, tetramethylenediamine, hexamethylenediamine and polyetherdiamine, carbamates such as hexamethylenecarbamate and ethylenediaminecarbamate. Can be given. Among these, as the component (C), preferred compounds are aliphatic diamines such as trimethylenediamine and hexamethylenediamine, or diaminecarbamates.

In the present invention, the blending amounts of the components (A), (B) and (C) preferably satisfy the following relationships in consideration of moldability, mechanical properties and dimensional stability. The compounding amount of the component (A) is preferably 50 to 70% by weight.
When the blending amount is less than 50% by weight, the content of the component (B) increases, and the water absorption rate of the composition increases. When it exceeds 70% by weight, mechanical properties are deteriorated and the effect of compounding the polyamide resin is reduced.

The blending amount of the component (B) is 30 to 50% by weight.
Is preferred. If it is less than 30% by weight, the mechanical properties are deteriorated, and if it exceeds 50% by weight, the water absorption rate becomes large, which causes problems such as dimensional changes during drying and water absorption, and large changes in mechanical properties. .. The components (A) and (B) used in the present invention are, as described above, in consideration of the dispersibility and structural stability of the disperse phase of the composition, in terms of their melt viscosities, a capillary type melt viscosity measuring device (Toyo Seiki Co., Ltd.). Let ηA and ηB (poise) be the melt viscosities of the resins measured at a molding temperature and a shearing rate of 1000 sec −1 by Capillograph (manufactured by Co., Ltd.), and the value of ηA / ηB is 0.5 to 1.5, It is preferable to select each of the components (A) and (B) that satisfy the relationship of preferably 0.7 to 1.3. When the value of η A / η B deviates from this range, the dispersibility of the disperse phase component of the composition comprising the components (A) and (B) deteriorates, resulting in poor fluidity and mechanical properties. There are cases.

The component (C) used in the present invention is preferably added in an amount of 0.05 to 5 parts by weight based on 100 parts by weight of the total of (A) and (B). More preferably, 0.1
~ 2 parts by weight. In this range, the component (C) can be selected in such an amount that the final composition produced by the production method of the present invention has desired fluidity. That is, if the blending amount of the component (C) is less than 0.05 parts by weight, the fluidity may be poor,
There is a problem that the paintability is not sufficiently improved,
If the blending amount of the component (C) exceeds 5 parts by weight, the effect is not equivalent to the blending amount, and rather the physical properties of the resulting composition may be impaired.

For the melt-kneading described in the present invention, a known melt-kneading device such as a twin-screw extruder can be used. The molding processing temperature at the time of melt-kneading each component is usually 220 to 32.
Within the range of 0 ° C., the temperature is set to 5 to 50 ° C. higher than the usual extrusion or molding temperature of the component (B). If the melt-kneading temperature is lower than 220 ° C., the melting of the raw materials will be insufficient and the desired composition cannot be obtained. Further, if the temperature is higher than 320 ° C., decomposition of the raw material occurs, which is not preferable.

The kneading order is not particularly limited, and (A),
Although (B) and (C) may be kneaded together, preferably, melt kneading is divided into two stages, (A) and (B) are previously melt kneaded in the first stage, and then (C) is kneaded in the second stage. Or the method of adding (C) during the melt-kneading of (A) and (B). The resin composition obtained by the production method of the present invention has other components such as a pigment, a dye, a heat stabilizer, an antioxidant, a weathering agent, a nucleating agent, and a lubricant as long as the moldability and the physical properties thereof are not impaired. , Plasticizers, antistatic agents, other polymers, etc.
It can be added in the molding process.

To the resin composition obtained by the production method of the present invention, an impact resistance improver, which will be described later, can be added in any production and molding process as long as its moldability and physical properties are not impaired. As the impact resistance improver, ethylene-propylene copolymer rubber, ethylene-propylene-
Examples thereof include rubbery substances such as diene terpolymer rubber, styrene-butadiene copolymer rubber, hydrogenated styrene-butadiene copolymer rubber, and polybutadiene rubber.

To the resin composition obtained by the production method of the present invention, an inorganic filler described below can be added in any production and molding process as long as the moldability and the physical properties thereof are not impaired. Examples of the inorganic filler include oxides such as iron oxide, alumina, magnesium oxide and calcium oxide, hydrated metal compounds such as aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate and calcium hydroxide, calcium carbonate and magnesium carbonate. Such as carbonate, talc, clay, bentonite, etc. silicate, barium borate, zinc borate, etc. borate, glass fiber, potassium titanate fiber, metal coated glass fiber, ceramic fiber, wollastonite, fiber Examples thereof include fibrous fillers such as magnesium oxysulfate.

The resin composition obtained by the production method of the present invention can be easily processed into molded articles of various shapes by any conventionally known molding method such as injection molding method and extrusion molding method. When the composition ratio of carbon, nitrogen, and oxygen elements on the surface of a molded article obtained by injection molding of the resin composition obtained by the present invention was determined by X-ray photoelectron spectroscopy analysis, the nitrogen element had a specific value of 7% or more. Was.

[0032]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. X-ray photoelectron spectroscopy analysis used in Examples and Comparative Examples of the present invention (hereinafter referred to as ESC
A) and various physical properties were measured based on the following test methods. (1) ESCA 150 mm x 150 mm x 2 m molded by injection molding
After cleaning the surface of the test piece of m with acetone and using the sample stored in a desiccator, use 2 x 10-8
After inserting into a measuring chamber of vacuum degree before and after Torr and continuing evacuation for about 1 hour, ESCA measurement was carried out for carbon, nitrogen and oxygen elements. The measuring device is KRATOS
XSAM800 manufactured by the company is used, and the radiation source is MgKα (125
3.6 ev), measurement area is 5 mm in diameter, and half width is 1.0
The measurement was performed under the condition of eV. (2) Melt viscosity Using a capillary type melt viscosity measuring device (Capillograph manufactured by Toyo Seiki Co., Ltd.), the melt viscosity at a set temperature of 280 ° C. and a shear rate of 1000 sec −1 was measured. (3) Melt Flow Rate (MFR) Based on ASTM-D1238, it is measured at a measurement temperature of 230 ° C. and a load of 2160 g. (4) Water Absorption Rate According to ASTM-D570, the test piece is immersed in warm water of 50 ° C. for 24 hours, and is calculated from the weight difference between when the test piece is molded (dry state) and after immersion. (5) Paintability 150mm x 150mm x 2m molded by injection molding
The urethane-based paint Retan PC60 (manufactured by Kansai Paint Co., Ltd.) was applied to the test piece of m without any special surface treatment.
It is applied to a thickness of 0 to 70 μm and left at 23 ° C. for 10 minutes. Then, it is dried in an oven at 80 ° C. for 30 minutes to obtain a coated test piece.

On the coating film of this test piece, a 1 mm square grid 10
0 cuts are made, cellophane tape is pasted on the cross, and then the cellophane tape is peeled off momentarily, and the paintability is evaluated by the number of the remaining crosses. Further, as the components (A), (B), and (C) used in the examples and comparative examples of the present invention, the following components were used. (A) Modified polypropylene resin (a) Modified polyolefin resin a-1: Grafted modified polyolefin resin Modified polypropylene resin obtained by grafting maleic anhydride at 0.5% by weight on a propylene homopolymer having an MFR of 5.5 g / min. -2: Graft-modified polyolefin resin Modified polypropylene resin obtained by grafting 0.8% by weight of maleic anhydride onto propylene / ethylene block copolymer having MFR of 35 g / min a-3: Multi-component modified polyolefin resin Ethylene, ethyl acrylate, anhydrous Multi-component modified polyolefin resin in which the weight ratio of maleic acid is E / EA / MAH = 69.9 / 27.0 / 3.1 (b) Polypropylene resin b-1: Propylene having MFR of 3.0 g / min. Homopolymer b-2: Propylene homopolymer with MFR of 30 g / min. Body b-3: Propylene / ethylene block copolymer having MFR of 16 g / min and ethylene content of 8% by weight (B) Polyamide resin B-1: Relative viscosity measured with a 1% solution in 96% sulfuric acid is 3 Polyamide 6 which is 10.10. Polyamide 6 which has a relative viscosity of 2.45 when measured in a 1% solution in 96% sulfuric acid is (C) Compound C-1 which contains at least one (C) amino group in one molecule. Trimethylenediamine C-2: Propylamine C-3: Hexamethylenediamine carbamate

[0034]

Example 1 (A) Modified polypropylene resin and (B) prepared by dry-blending (a) modified polyolefin resin and (b) polypropylene resin in a Henschel mixer in the predetermined amounts shown in Table 1. After blending polyamide resin and mixing with Henschel mixer, twin-screw extruder with vents in the same direction (internal diameter 45 mm, L / D = 30)
Melt-kneading was carried out according to the procedure, and the component (C) was added midway through the extruder, and further melt-kneaded to prepare pellets.

After heating and drying the pellets at 100 ° C. for 2 hours, various physical properties were measured according to the above-mentioned test methods.

[0036]

Examples 2 to 6 The same as Example 1 except that the kneading components and blending amounts are as shown in Table 1.

[0037]

Comparative Examples 1 to 5 The same as Example 1 except that the kneading components and the blending amounts are as shown in Table 1.

[0038]

[Table 1]

[0039]

As described above, according to the manufacturing method of the present invention, the excellent properties of the polypropylene resin and the polyamide resin are not impaired, the water absorption is low, and the moldability and coatability are excellent. A resin composition can be obtained. Therefore,
The composition obtained by the production method of the present invention is small in physical property change and dimensional change due to water absorption, and has good adhesion to a coating material without performing a special surface treatment off-line, so that a material that can be applied online can be used. In addition to being suitably used as a member such as an automobile exterior or outer plate, it can be suitably used as any member that requires paintability or printability.

Claims (2)

[Claims] 1. A polymer containing (A) (a) a modified polyolefin resin, (b) a modified polypropylene resin composed of a polypropylene resin, (B) a polyamide resin, and (C) an amino group in one molecule. A method for producing a resin composition, which comprises melt-kneading at least one compound selected from compounds. 2. The component (C) comprises amines, diamines,
The method for producing a resin composition according to claim 1, which is selected from at least one kind of diamine carbamates.