JPS62267344A - Production of filler-containing polypropylene resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent surface processabilities such as adhesivity, paintability, etc., impact resistance and heat- resistance and suitable as automobile parts, etc., by compounding a specific modified polypropylene resin, an ethylene copolymer and a filler at specific ratios. CONSTITUTION:The objective composition can be product by (1) melting and mixing (A) 27-87(wt)% polypropylene resin having a melt index of 0.5-100g/10min, (B) 3-15% modified polypropylene resin containing 0.1-3mol% unsaturated dicarboxylic acid anhydride constituent unit (e.g. maleic anhydride unit) and (C) 5-40% filler (e.g. talc) preferably produced by treating the surface of 100g of a filler with 0.05-2g of an aminosilane compound and (2) melting and mixing the resultant mixture with (D) 5-30% ethylene copolymer composed of 82-98.7mol% ethylene constituent unit, 1-15mol% ester constituent unit selected from alkyl acrylate, etc., having 1-8C alkyl group and 0.3-3mol% unsaturated dicarboxylic acid anhydride constituent unit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a filler-containing polypropylene resin composition.

In recent years, filler-containing polypropylene resins have been extremely actively applied to automobile parts and home appliance parts because of their excellent mechanical and thermal properties.

Taking automobile parts as an example in particular, interior parts such as instrument panels, trims, and pillars are coated with nonwoven fabrics, fabric foam, vinyl chloride leather, etc. to improve the quality of interior windows. It is often used to bond two skin materials together.

Additionally, there is a movement toward increasing the fashionability of bumpers as exterior parts by applying paint to their surfaces and integrating them with the body color.

On the other hand, printing is also frequently used on parts of home appliances to increase their decorativeness.

The present invention relates to a molding method for a resin composition that can improve surface processability such as adhesion, paintability, and printability, and provide a molded product having both impact resistance and heat resistance.
It is intended to be used as the above-mentioned automobile parts and home appliance parts. [Prior art] Since polypropylene resin is scratch-free, it is difficult to perform surface treatments such as adhesion and paintability. many.

A well-known method to improve this problem is to add a filler to polypropylene, but although this method can improve to some extent depending on the type and amount of filler, it is largely impractical. there were.

In order to improve the compatibility between polypropylene, adhesives, and paints, a medium called a primer is usually added between them, for example, a medium consisting of chlorinated polypropylene and toluene, which is known as a typical composition. is used.

However, the primer itself is expensive, and the addition of a new step makes the final product expensive, so further improvements are desired.

[Problem that the invention seeks to solve]

Therefore, in order to improve these, for example, in the case of adhesion, it has been considered and applied to modify and modify the surface of polypropylene molded products by physical or chemical methods. This method is more complicated than the primer application step, and depending on the etching conditions, the molded product may be deformed or the effect may be insufficient.

In addition, in the case of painting, methods are being adopted to improve paintability by oxidizing and polarizing the surface of the molded product by plasma irradiation instead of applying a primer, but the fact that the plasma irradiation process is the Basochi system; Also, depending on the shape of the molded product, the degree of treatment may be non-uniform, and as a result, satisfactory results are not necessarily obtained at present.

Furthermore, as an attempt to impart polarity to polypropylene itself, as described in, for example, JP-A-50-76149 or JP-B-51-10264, polypropylene was treated with acrylic acid in the presence of an initiator such as an organic peroxide. An improved method of graft modification with acids, unsaturated carboxylic acids such as maleic anhydride, or their anhydrides;
Alternatively, a method has also been proposed in which the graft modified product is blended with unmodified polypropylene.

However, in this method, the amount of unsaturated carboxylic acid or its anhydride introduced by graft modification is limited because the decomposition reaction of polypropylene by peroxide occurs simultaneously, and as a result, the surface modification effect is insufficient. However, even if they are effective, they have the drawback of problems with mechanical properties due to lower molecular weight.

As a filler-containing polypropylene resin composition that solves the above-mentioned drawbacks and has excellent adhesion, paintability, and printability, we first selected polypropylene resins, ethylene structural units, alkyl acrylates, and alkyl methacrylates. We have found a composition comprising an ethylene copolymer comprising an ester structural unit and an unsaturated dicarboxylic anhydride structural unit, and a filler. , (Special request Showa 6
(No. 0-165584) However, although the filler-containing polypropylene resin composition can sufficiently obtain the target surface modification effect, the effect of adding a filler to improve rigidity is not sufficiently exhibited, and the thermal properties are unsatisfactory. there were.

An object of the present invention is to provide a method for producing a filler-containing polypropylene resin composition that overcomes the above-mentioned drawbacks and has excellent adhesiveness, paintability, printability, etc.

Still another object is to provide a filler-containing polypropylene resin composition that has excellent adhesiveness, paintability, printability, and the like.

[Means for solving problems]

In order to achieve the above object, the present inventors have developed polypropylene resins, modified polypropylene resins having unsaturated dicarboxylic anhydride constituent units, ethylene constituent units, esters selected from alkyl acrylates and alkyl methacrylates. As a result of intensive studies on the production method of a composition consisting of an ethylene copolymer consisting of a structural unit and an unsaturated dicarboxylic acid anhydride structural unit, and a filler, we found that it is possible to recover the rigidity of the filler-containing polypropylene and improve the thermal properties. Since the improvement was observed to be significant, the present invention was developed.

That is, the present invention comprises (A) 27 to 87% by weight of polypropylene resin, (B)
0.1 to 3 mol% of unsaturated dicarboxylic anhydride constituent units
3 to 15% by weight of a modified polypropylene resin, (C) 82 to 98.7 mol% of ethylene structural units, and an ester composition selected from alkyl acrylates and alkyl methacrylates having an alkyl group having 1 to 8 carbon atoms. Ethylene copolymer 5 having 1 to 15 mol% of units and 0.3 to 3 mol% of unsaturated dicarboxylic anhydride constituent units
~30% by weight, and (D) filler 5 to 40% by weight, in the first step, component (A), component (B), and component (D) are melted. Mix to obtain composition (E), then mix composition (E) and component (C).
The present invention relates to a method for producing a filler-containing polypropylene resin composition, which comprises melt-mixing the filler-containing polypropylene resin composition.

Hereinafter, the configuration of the present invention will be specifically explained.

(A) Polypropylene resin The polypropylene resin used in the present invention includes crystalline polypropylene, crystalline propylene/ethylene block or random copolymer, crystalline propylene/α-
Olefin copolymers (α-olefins have 4 to 10 carbon atoms) can be used alone or in the form of a mixture of two or more.

In addition, the melt index of the polypropylene resin (
(based on JIS K6758) is usually 0.5 to 100
g/10 minutes, preferably 1 to 50 g/10 minutes.

(B) Modified polypropylene resin The modified polypropylene resin used in the present invention refers to a polypropylene resin having 0.1 to 3 mol% of unsaturated dicarboxylic anhydride constituent units.

As the polypropylene resin, the component (A) described above is used.
It is. Furthermore, examples of monomers having an unsaturated dicarboxylic anhydride constitutional unit include maleic anhydride, citraconic anhydride, itaconic anhydride, and tetrahydrophthalic anhydride, among which maleic anhydride is most preferred. preferable.

The amount of these unsaturated dicarboxylic anhydride structural units contained in the polypropylene resin is in the range of 0.1 to 3 mol%.

If it is less than 0.1 mol%, the component (
The bond between A) and component (D) is weak, and component (D) is
), and the component (C) that is melt-mixed in the second stage aggregates, making it impossible to find the desired rigidity. The upper limit of 3 mol% is a production limit, and if the content is higher than this, the amount of free anhydride will increase, causing problems such as the generation of bubbles. ) is sufficient for immobilization.

(C) Ethylene copolymer The ethylene copolymer used in the present invention contains 82 to 98.7 mol% of ethylene structural units and is selected from alkyl acrylates and alkyl methacrylates having an alkyl group having 1 to 8 carbon atoms. 1 to 15 mol% of ester constituent units, 0.3 to 3 of unsaturated dicarboxylic anhydride constituent units
% by mole.

Examples of monomers having an ester structural unit contained in the ethylene copolymer include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, and butyl methacrylate (hereinafter referred to as ``butyl methacrylate''). saturated ester compounds).

The amount of ester structural units contained in the ethylene copolymer is in the range of 1 to 15 mol%, preferably 3 to 12 mol%. Outside this range, when a filler-containing polypropylene resin composition is prepared, the compatibility with the polypropylene resin may be poor, and the effect of improving mechanical properties such as impact resistance may be poor, which is not preferable.

Examples of the monomer having an unsaturated dicarboxylic anhydride constitutional unit include maleic anhydride, citraconic anhydride, itaconic anhydride, and tetrahydrophthalic anhydride, among which maleic anhydride is most preferably used.

The amount of these unsaturated dicarboxylic anhydride structural units contained in the ethylene copolymer is in the range of 0.3 to 3 mol%, preferably 0.5 to 2.8 mol%. If it is less than the lower limit, there will be insufficient polar groups to participate in surface processing and the improvement effect will be lacking, and if it is more than the upper limit, the polarity will be too strong and it will not be compatible with polypropylene resin. Don't tolerate it.

The method for producing the ethylene copolymer is not particularly limited, and known methods such as solution polymerization, emulsion polymerization, and high-pressure bulk polymerization can be applied. Among these, the most common is a high-pressure polymerization method in which copolymerization is carried out with ethylene in the presence of a radical generator at 500 to 3000 atm and 100 to 300°C in the presence or absence of an appropriate solvent or chain transfer agent. . In such a high-pressure polymerization method, a suitable method is to apply a solution in which the above-mentioned unsaturated dicarboxylic acid anhydride is dissolved in the above-mentioned unsaturated ester compound to an internal pressure using a high-pressure pump, and then directly transport the solution into a tower-shaped or tubular reactor. . Melt index of the ethylene copolymer thus obtained (JISK 67
60) is suitable in the range of 0.5 to 800 g/10 minutes, preferably in the range of 1 to 200 g/10 minutes.

If the melt index is smaller than the lower limit, it lacks compatibility with the polypropylene resin, and if it is larger than the upper limit, the rigidity, heat resistance, and surface hardness, which are the characteristics of the liquid composition when used as a filler-containing polypropylene resin composition, are reduced. This is not preferable because the decrease in

(D) Filler Among the fillers used in the present invention, the inorganic fillers are not particularly limited, but include calcium carbonate, talc, clay, silica, diatomaceous earth, alumina, zinc white, magnesium oxide,
Preferred are mica, calcium sulfite, calcium sulfate, calcium silicate, glass fibers, glass fibers (including those treated with silane), asbestos, gypsum fibers, and the like. The organic filler is also not particularly limited, but various wood flours, cellulose fibers, melamine powder, etc. are preferred.

These may be used alone or in combination if necessary. Furthermore, talc and/or mica are more preferred in view of the balance between impact resistance and heat resistance retention of the filler-containing polypropylene resin composition.

Furthermore, if the filler used in the present invention is subjected to surface treatment if necessary, the balance between rigidity and impact strength is improved, and a filler-containing polypropylene resin composition with a high water resistance can be obtained.

As surface treatment agents, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, T-aminopropyltrimethoxysilane, N-(β- aminoethyl)-r-aminopropyltrimethoxysilane, N-(β-aminoethyl)
-γ-Aminopropylmethyltrimethoxysilane, γ-
Mention may be made of organosilane compounds such as glycidoxymethoxysilane, but especially N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(β-aminoethyl)-r-aminopropylmethyltrimethoxysilane. A filler-containing polypropylene resin composition with high reactivity and the highest level of balance between rigidity and impact strength can be obtained.
preferable.

The blending ratio of the surface treatment agent is 0.1 to 1.5 parts by weight, preferably 0.3 to 1.5 parts by weight, per 100 parts by weight of the filler.
It is in the range of 0 parts by weight.

If it is less than the lower limit, component (A), component CB) and component (
D) The bond is weak, the rigidity due to the filling effect of the filler is not expressed, and the impact strength is also poor. Above the upper limit, the effect of adding the surface treatment agent becomes saturated, resulting in poor economic efficiency. In addition, as a processing device, a ribbon mixer, a super mixer, etc. are preferable.

(E) Composition ratio In the method for producing a filler-containing polypropylene resin composition of the present invention, the composition ratio of component (B) modified polypropylene resin having an unsaturated dicarboxylic anhydride structural unit is the same as component (A) polypropylene resin. 3 to 15% by weight
is preferred.

If the composition ratio of component (B) is less than 3% by weight, filler (D)
If the desired stiffness is not obtained, and if it exceeds 15% by weight,
Although the filler (D) satisfactorily achieves the desired rigidity, physical properties such as impact strength deteriorate, and it is not economically advantageous.

The composition ratio of the component (C) ethylene copolymer in the method for producing a filler-containing polypropylene resin composition of the present invention is as follows:
5 to 30% by weight, particularly preferably 10 to 20% by weight.

When the composition ratio of the ethylene copolymer (C) is less than 5% by weight, almost no effect of surface processability modification such as adhesion, paintability and printability is observed, and when it exceeds 30% by weight, the resulting composition Physical properties such as rigidity and heat resistance deteriorate, and no effect of increasing the amount of surface workability is observed.

The composition ratio of the filler CD) in the method for producing a filler-containing polypropylene resin composition of the present invention is 5 to 40% by weight, particularly preferably 10 to 40M%.

If the composition ratio of filler (D) is less than 5% by weight, high rigidity and thermal properties (such as heat distortion temperature, etc.), which are essential conditions for the composition in the present invention, will not be improved, and if it exceeds 50% by weight, The impact resistance of the composition is extremely reduced, and it is used in automobiles.
It lacks practicality as a material for exterior parts, and no effect on increasing thermal properties is observed.

(F) Production method and molding method The physical properties of the filler-containing polypropylene resin composition according to the present invention are achieved only when the composition ratio of the composition and the kneading production method specified below are combined.

That is, in the first stage of kneading, component (A) and component (B)
and composition (E) by melt-mixing component (D).
and then in a second step, composition (E) and component (C) are melt-mixed to obtain a composition according to the invention.

In addition, when kneading and manufacturing the filler-containing polypropylene resin composition according to the present invention, styrene-butadiene random copolymer, styrene, etc. various styrenic elastomers such as butadiene broxol copolymer and its hydrogenated products, various polyolefin elastomers such as amorphous ethylene-propylene copolymer, ethylene-propylene-dicyclopentadiene copolymer, and may be additionally mixed with various functional group-containing polyolefins such as a glycidyl group-containing ethylene copolymer.

It is also possible to add appropriate amounts of various additives such as antioxidants, weathering agents, antistatic agents, foaming agent colorants, and the like.

As the equipment for kneading and producing the filler-containing polypropylene resin composition according to the present invention, a Banbury mixer, an 11-screw or twin-screw extruder, a roll kneader, or other conventional kneading equipment for plasti-nox or rubber is used. However, since the composition has polarity and adheres to metal in the molten state, an extruder-type kneading device is preferable.

In addition, an extruder with two or more feed zones can perform the first stage of melt mixing and the second stage of melt mixing in one process, which has great economic advantages (very useful).

A desired molded article can be obtained from the composition obtained according to the present invention by applying injection molding, extrusion molding, blow molding, etc., which are generally used in molding polypropylene resins.

(G) Properties, uses, etc. The filler-containing polypropylene resin composition according to the present invention has excellent adhesiveness, paintability, printability, etc., and also has excellent mechanical properties. Demonstrate together. That is, (1) it is possible to obtain an injection molded article with a complex, thin-walled shape under conventional molding conditions without substantially reducing the inherent fluidity of filler-containing polypropylene.

(2) The decrease in mechanical properties such as rigidity is small, and in particular, impact resistance is greatly improved.

(3) When filler-containing polypropylene is used, easily noticeable weld lines (weld refers to melted resin flowing from two or more directions and welding) lines are less noticeable in the composition of the present invention.

The filler-containing polypropylene resin composition obtained by the present invention exhibits the above-mentioned excellent effects and can be used in fields where adhesion, painting, and printing are required.

List typical usage examples.

■ Automotive exterior parts such as bumpers, bumper corners, etc. ■ Automotive interior parts such as instrument panels, meter cases, glove boxes, console boxes, trims and pillars, etc. ■ Motorcycle parts such as fenders, leg seals, etc. ■ Laundry Parts of home appliances such as machine lids, evacuation machine bodies, fan stands, ventilation fan frames, etc.

〔Example〕

EXAMPLES The present invention will be explained in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited by these.

(1) Method for producing ethylene copolymer samples 1. In a 2-liter reactor equipped with a stirrer, ethylene containing a small amount of propane as a chain transfer agent and maleic anhydride were mixed with various unsaturated ester compounds listed in Table 1. 1.5 to 3.0 kg/- under a pressure of 1.600 kg/- while controlling the polymerization temperature at 180°C.
Copolymerization was carried out at a rate of 2 kg/hr to obtain various samples shown in Table 1.

(2) Method for measuring physical properties in the present invention ■ Wet stretch crab Measurement was carried out at 23°C in accordance with JISK 6768-1977.

As a test piece for measurement, a 3.5 oz.
A plate of 9Q x 21 Otori was molded and presented.

■Adhesive strength: Approximately 150 g/t of a mixture of Cemedine G 25097% by weight and Dismodule 3% by weight was applied as an adhesive to the same plate used for the wet tension test.
Apply ri using an air spray gun and heat at 80°C for 2 minutes. On the other hand, in parallel with this, PPX manufactured by Toshi was heated as a skin material at 110℃ for 2 minutes, and the surface pressure was immediately increased to 0.2 kg/
Press and adhere with cnl pressure. 23℃, 65±5%R
300 ms/mi after being left in the H environment for 7 days.
A 180° peel test was performed at a speed of n to measure the strength.

■Initial adhesion of coating: 1. The same plate used for the wet tension test. l, 1-1-lichloroethane vapor (74℃
) for 30 seconds, dry at room temperature, and then directly apply urethane paint (manufactured by Nippon B Chemical Co., Ltd., Flexene #1).
01) was spray-painted and heated for 30 minutes in an open environment at 120℃.
A minute baking was done to finish.

Use a razor blade to carve 100 goban marks (1Q vertically
After crimping a piece of cellophane tape (manufactured by Chiban Co., Ltd.) with a finger to a 4 mm wide Cellotape ■, the end surface was grasped and peeled off at once, and the number of gobbles remaining was evaluated as a residual rate (%).

■Izotsu impact strength: 23 according to JISK7110
Performed at °C. A 10-ounce test piece molded using a screw in-line injection molding machine manufactured by Sumitomo Heavy Industries Co., Ltd. was provided as a test piece for measurement.

■Heat distortion temperature: Bending stress 4 according to JISK7207
, 6 k+r/cni. The test piece for measurement was molded in the same manner as the Izot impact test piece.

■Bending elastic modulus: Conducted at 23°C in accordance with JTSK7203. The test piece for measurement was molded in the same manner as the Izot impact test piece.

Examples 1 to 9 and Comparative Examples 1 to 12 According to the distribution ratio in Table 2, Noprene@AW564 (melt index 8) was used as the polypropylene resin.
g/10mln, ethylene content 6% by weight, ethylene content in the propylene and ethylene copolymerization part is 40% by weight, and the intrinsic viscosity of the copolymerization part in a tetralin solution at 135°C is 8.
dl/g (ethylene-propylene block copolymer), modified polypropylene resin PP-II (ethylene content 1
0% by weight of ethylene-propylene copolymer), modified polypropylene resin PP-II having 0.05 mol% of maleic anhydride structural units (ethylene-propylene copolymer with 10% by weight of ethylene), ethylene copolymer coalescence (details for each sample are shown in Table 1), filler (talc;
Average particle size (according to sedimentation particle size distribution measurement, corresponding to 50% cumulative distribution) 3.0μ, mica; average particle size 3.5
μ) and various aminosilane compounds as surface treatment agents for fillers (T-aminopropyltriethoxysilane: TSL8331 manufactured by Toshiba Silicone Co., Ltd., N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane: TSL8340 manufactured by Toshiba Silicone Co., Ltd. , N-(β-aminoethyl)
-γ-aminopropylmethyltrimethoxysilane: TSL8345 manufactured by Toshiba Silicone Company, γ-glycidoxypropyltrimethoxysilane: TSL8 manufactured by Toshiba Silicone Company
350, γ-meccryloxypropyltrimethoxysilane: TSL 8'370 (manufactured by Toshiba Silicone) and Irganox Co., Ltd. 1010 (manufactured by Ciba Geigy) to 100 parts by weight of the above formulation. )0.2
Part by weight, 0.05 part by weight of calcium stearate and Ultranox@626 (manufactured by BorgWarner) 0
．． 05 parts by weight were added and mixed using a powder mixer, and then melt-kneaded using a 65-inch diameter vented extruder (manufactured by Ikegai Iron Works, L/D 28) set at a die temperature of 220°C.

Comparative Examples 1 to 6 in Table 2 are compositions in which each component was simply melt-kneaded in one step.

Examples 1 to 9 and Comparative Examples 7 to 12 were first melt-kneaded using the blending ratios of each component listed in the upper row of Table 2. For example, in the case of Example 1, AW564/PP-11/TSL834 was used.
AW564/PP-n/Surface treated talc = 61°115.6/ A pellet-like composition (E) was obtained (compounding ratio of 33.3), and then the components listed in the lower column were melt-kneaded with the composition (E) in the blending amounts listed in the lower column using a 651 heavy-diameter extruder. It is a composition. (For example, in the case of Example 1, the blending ratio of ethylene copolymer (C)/composition (E) is 10/90.) For these various composition acid samples, wetting tension and adhesion were determined by the method described above. Strength, initial coating adhesion, isot impact strength, heat distortion temperature, and flexural modulus were measured.

The results are summarized in Table 2.

As is clear from Table 2, it can be seen that the examples according to the present invention have an excellent balance of physical properties compared to the comparative examples lacking the constituent elements of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, excellent adhesiveness,
It is an object of the present invention to provide a method for producing a filler-containing polypropylene resin composition that has surface processability such as paintability and printability, and also has impact resistance and heat resistance, and a composition and a molded product thereof produced by the method. can.

Claims (5)

[Claims] (1) (A) Polypropylene resin 27-87% by weight (
B) 3 to 15% by weight of a modified polypropylene resin having 0.1 to 3 mol% of unsaturated dicarboxylic anhydride constitutional units, (C) 82 to 98.7 mol% of ethylene constitutional units, and 1 carbon number. An ethylene copolymer comprising 1 to 15 mol% of ester constituent units selected from alkyl acrylates and alkyl methacrylates having ~8 alkyl groups and 0.3 to 3 mol% of unsaturated dicarboxylic anhydride constituent units. 5
~30% by weight, and (D) filler 5 to 40% by weight, in the first step, component (A), component (B), and component (D) are melted. Mix to obtain composition (E), then mix composition (E) and component (C).
A method for producing a filler-containing polypropylene resin composition, the method comprising melt-mixing the filler-containing polypropylene resin composition. (2) Claim 1, wherein the unsaturated dicarboxylic anhydride constituting components (B) and (C) is maleic anhydride.
A method for producing a filler-containing polypropylene resin composition as described in 1. (3) The method for producing a filler-containing polypropylene resin composition according to claim 1, wherein the component (D) filler is talc and/or mica. (4) The filler-containing polypropylene resin composition according to claim 1, wherein the filler (D) is surface-treated with 0.05 to 2% by weight of an aminosilane compound per 100% by weight of the filler. Production method. (5) Component (D) The aminosilane compound for surface treatment of the filler is N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and/or N-(β-aminoethyl)-γ-aminopropylmethyl The method for producing a filler-containing polypropylene resin composition according to claim 4, wherein the filler-containing polypropylene resin composition is trimethoxysilane.