JPH0753812A - Amino group-containing polypropylene resin composition - Google Patents

Abstract

PURPOSE:To obtain a polypropylene resin composition preferably suitable for uses such as automotive parts, electric.electronic parts, mechanical parts, toys, stationery, daily necessities, sheets and films, especially uses requiring coating.printing.adhesion, having improved adhesivity.adhesiveness of coating film. CONSTITUTION:This amino group-containing polypropylene resin composition is the polypropylene resin composition comprising 0.1-95 pts.wt. of crystalline polypropylene (A) and 99.9-5 pts.wt. of a primary amino group-containing modified polypropylene and contains 0.5X10<-2> mew (CH3ONa)/g(PP) primary amino group amount in the resin composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polypropylene resin composition having excellent coating film adhesion and adhesion. The polypropylene resin composition of the present invention is used for automobile parts, electric
Electronic parts, machine parts, toys, stationery, daily necessities, sheets,
It is preferably used in the field of films and the like, especially for applications that require painting, printing and adhesion.

[0002]

2. Description of the Related Art Crystalline polypropylene is used in the fields of automobile parts, electric / electronic parts, mechanical parts and the like because it has excellent mechanical properties and electrical properties and is easily molded. However, polypropylene has drawbacks in coating film adhesion, adhesiveness, etc., which are obstacles to new practical application.

Means for improving the coating adhesion of polypropylene include dry surface treatment methods such as flame treatment method, plasma treatment method, ozone treatment method, corona discharge treatment method, ultraviolet ray or electron beam irradiation treatment method, and the like. Wet surface treatment methods such as treatment with a chromic acid mixture or mineral acid such as concentrated sulfuric acid, chemical grafting of surface modification components on the surface of the molded body, and direct application of the surface modification layer A primer coating method and the like can be mentioned. However, these methods have the following drawbacks in their implementation.

In the dry surface treatment method, not only the shape of the object to be treated is extremely limited, but also the treatment effect is notably deteriorated with time after leaving the treatment, and the modification effect by the treatment is not always sufficient. Many. In addition, there is a disadvantage in that it is economically disadvantageous because an expensive processing device is used. For example, in the plasma processing method, since a high vacuum condition is required, it is necessary to install an expensive device, and it is difficult to avoid an increase in cost due to the batch method. Furthermore, the surface after plasma treatment is unstable, and if it comes into contact with foreign matter, the adhesiveness of the paint will decrease, so there may be variations in coating adhesion performance.
It was very difficult to handle.

Although the wet treatment method can obtain a relatively high reforming effect, it has disadvantages that it requires the use of harmful chemicals and is not suitable for continuous production because it requires a complicated treatment process. Regarding the primer coating method, usually, 1, 1,
Surface treatment such as steam cleaning with a halogenated hydrocarbon solvent such as 1-trichloroethane is required. However, the use of 1,1,1-trichloroethane is being regulated due to the ozone problem which is one of the recent environmental measures.
Further, in the primer coating method, there is a drawback that an expensive primer must be used and that the coating cost is increased due to the large number of coating steps, but in addition to that, it is necessary to volatilize the solvent of the primer. Therefore, there was a problem from the viewpoint of environmental hygiene and from the danger of fire.

On the other hand, a method of improving coating film adhesion by blending another synthetic resin or additive as a surface modifier with a polypropylene resin is economical because treatment equipment and treatment steps are simple. It is of great value and has received a great deal of attention in recent years. For example, JP-A-2-102239, JP-A-4-63817, and JP-A-4-1267.
In JP 40, a surface modifier is kneaded in a synthetic resin, and the surface modifier is transferred to the surface of the molded body by using the affinity between the modifier and the molded substrate as a driving force to improve coating film adhesion. A method is disclosed. However, even in the above method, due to the synthetic resin and additives to be blended, often,
Physical properties such as rigidity and heat resistance are significantly reduced, or
Since the modifying effect strongly depends on the molding method, there is a drawback that the modifying effect is insufficient when applied to a molding method such as injection molding having a short molding cycle.

A method for reacting a maleic anhydride-modified polypropylene with a diamine compound to improve the dyeability of polypropylene is disclosed in Japanese Patent Publication No. 44-1540. Further, JP-B-56-9925 and JP-B-58-8683 disclose a method of adding a diamine compound in order to suppress an irritating odor generated during the production of maleic anhydride. Furthermore, JP-A-3-281608 and JP-A-3-28164
Japanese Patent Publication No. 6 discloses a method of forming a crosslinked structure with an amino group-containing compound in order to improve the impact resistance of polypropylene. However, in these inventions, a general amino group-containing compound is used, and since the aggregation state of the amino group-containing compound component in the matrix is not suitable for improving the coating adhesion, such acid modification is used. A modified polypropylene obtained from polypropylene and an amino group-containing compound does not exhibit good coating film adhesion and adhesion.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polypropylene resin composition having extremely excellent coating film adhesion and adhesiveness.

[0009]

[Means for Solving the Problem] In order to improve the coating film adhesion and adhesiveness by introducing a polar group as a surface-modifying component into polypropylene resin, the introduced polar group is oriented on the surface side of the molded article. , It is necessary to increase the affinity with paints.
The present inventors have previously proposed a technique for efficiently orienting polar groups introduced into a resin toward the surface of a molded body in the molding process (Japanese Patent Application No. 04-2345). The orientation of the polar groups to the surface side is driven by the affinity of the introduced polar groups with the surface of the molded substrate, but it is necessary to design the material from the material side so that the surface orientation of the polar groups can proceed in a short time. . The present inventors have studied the improvement of the coating film adhesion of polypropylene resin by utilizing the orientation phenomenon of the surface modifying component on the surface side. As a result, in the case of modifying polypropylene resin, (1) coating film of polypropylene resin In order to improve adhesion and adhesion, it is effective to introduce a primary amino group into the polypropylene molecular chain through a chemical bond. (2) A surface-modifying component 1
The primary amino groups do not aggregate in the polypropylene matrix and desirably do not molecularly disperse to form an aggregate, and (3) the primary amino groups introduced into the polypropylene resin are formed on the surface of the molded article in a short time. It has been found that it is important to satisfy the three requirements that the binding part between the amino group and the polypropylene molecular chain has a flexible molecular structure so that it can be oriented.

The present inventors have completed the present invention as a result of studying a polypropylene resin having excellent coating film adhesion and adhesiveness based on the above findings. That is, the polypropylene resin having excellent coating film adhesion / adhesion of the present invention means a modified polypropylene (B) 9 having 0.1 to 95 parts by weight of crystalline polypropylene (A) and a primary amino group.
A polypropylene resin composition consisting of 9.9 to 5 parts by weight, wherein the amount of primary amino groups in the resin composition is 0.5 × 1.
0 is _{^{-2 meq (CH 3 ONa) /}} g amino group-containing polypropylene resin composition characterized in that contained (PP) or more.

The proportion of (A) and (B) is preferably (A) 0.5 to 50 parts by weight, and (B) 99.5 to 50.
It is good to select from the range of 95 to 60 parts by weight with respect to (B) 5 to 40 parts by weight, and more preferably 5 to 40 parts by weight. The amino group-containing polypropylene resin composition of the present invention has a primary amino group content of 0.5 × 10 ^-2 meq determined by a titration method.
When it is (CH ₃ ONa) / g (PP) or more, practically sufficient coating film adhesion can be obtained, and the primary amino group content in the resin composition impairs mechanical performance as a material. It can be increased unless it is increased. Preferably 0.5 × 10 ⁻² to 50 × 10 ⁻² , more preferably 1.
0 × 10 ^-2 to 10 × 10 ^-2 meq (CH ₃ ONa) / g
(PP). The primary amino group content shown here is the content of the primary amino group introduced into the polypropylene molecule by a chemical bond, and is the primary amino group of the unreacted amino group-containing compound component remaining in the polypropylene resin. Is excluded. Further, in order to obtain a strong coating film adhesion, it is preferable that the matrix has a uniform phase structure in which the amino group-containing compound component is dispersed substantially in a molecular state without aggregating. When the primary amino group component is aggregated in the amino group-containing polypropylene resin composition, the surface orientation of the amino group to the surface of the molded body does not occur effectively on the molded body surface in a short time, and the molding cycle such as injection molding is performed. The effect of improving the coating film adhesion / adhesiveness of the molded product obtained by the molding method in a short time is not sufficient. To obtain practically sufficient coating adhesion,
The aggregate diameter of the amino group-containing compound component is preferably 0.1 μm or less. Hereinafter, the raw materials of the amino group-containing polypropylene resin composition and the method for producing the same will be specifically described. (1) Crystalline polypropylene The crystalline polypropylene used in the amino group-containing polypropylene resin composition disclosed in the present invention is a crystalline resin selected from polypropylene and polypropylene-α-olefin copolymer. That is, in addition to propylene homopolymer, for example, 1 to 30% by weight of ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, etc. Random copolymers obtained by copolymerizing one or two or more of the α-olefins, and propylene-α-olefin block copolymers containing 1 to 40% by weight of these α-olefins. The crystalline polypropylene has a melt index of 0.05 to 100 g / 10.
Minutes, particularly 0.1 to 40 g / 10 minutes are suitable. Crystalline polypropylene can be obtained, for example, by reacting in the presence of a combination catalyst of titanium trichloride and an alkylaluminum compound, which is usually called a Ziegler-Natta type catalyst. (2) Modified polypropylene having a primary amino group The modified polypropylene having a primary amino group used in the amino group-containing polypropylene resin composition disclosed in the present invention is not particularly limited in its production method. As disclosed in JP-B-44-1540, it is produced by a method in which an acid-modified polypropylene to which an unsaturated carboxylic acid and / or a derivative thereof is added is reacted with two or more amino group-containing compounds in one molecule. be able to. Hereinafter, 1 using acid-modified polypropylene as a raw material
The method for producing a modified polypropylene having a primary amino group will be described in detail. (2-1) Acid-modified polypropylene The acid-modified polypropylene used in the production of the modified polypropylene having a primary amino group has an unsaturated carboxylic acid and / or a derivative thereof in an amount of 0.01 to 5% by weight with respect to the crystalline polypropylene. %, Preferably 0.1 to 3% by weight of acid-modified polypropylene added. When the addition amount is 0.01% by weight or less, the primary amino group content of the modified polypropylene having primary amino groups is 0.5 × 1.
It becomes difficult to reach 0 ⁻² meq (CH ₃ ONa) / g (PP) or more, and the effect of improving the coating film adhesion of the resulting polypropylene resin composition is not sufficient. On the other hand, when the content is 5% by weight or more, not only is it uneconomical, but the aggregation of the amino group-containing compound component is remarkable in the resin composition, and the amount of the primary amino group introduced increases, but the coating film adheres. On the contrary, the strength decreases. Further, in the present invention, the molecular weight is 20,
The acid-modified polypropylene characterized by being 000 or more can be preferably used. When the molecular weight of the acid-modified polypropylene is 20,000 or less, the amino group component often agglomerates in the resin composition to cause phase separation, and in this case, the coating film adhesion is greatly reduced. In order to control the addition amount and the molecular weight of the unsaturated carboxylic acid and / or its derivative in the acid-modified polypropylene, it is possible to control the molecular weight of the crystalline polypropylene as the raw material and the conditions for the addition reaction. Here, the molecular weight means the weight average molecular weight, and can be measured by GPC (gel permeation chromatography).

The unsaturated carboxylic acid or its derivative added to the crystalline polypropylene is, for example, maleic acid,
Fumaric acid, itaconic acid, chloromaleic acid, citraconic acid, allylsuccinic acid, mesaconic acid, aconitic acid, and other dicarboxylic acids and their acid anhydrides, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid, Examples thereof include carboxyl group-containing monomers such as maleic acid. Of these, maleic anhydride, acrylic acid and methacrylic acid are preferred, and maleic anhydride is most preferred.
These monomers can be used alone or in combination of two or more. Further, as disclosed in JP-A-1-236214, by causing an unsaturated aromatic monomer to coexist and react at a specific ratio, the amount of unsaturated carboxylic acid or its derivative added is increased. be able to.

The method for producing the acid-modified polypropylene includes
A method of dissolving crystalline polypropylene by heating in an organic solvent such as xylene and reacting it in the presence of a radical generator (solution method), or heating and melting crystalline polypropylene above its melting point and reacting in the presence of a radical generator. It can be performed by a known method such as a method (melting method). In the solution method, it is preferable to use an aromatic solvent such as toluene or xylene as the organic solvent, and the reaction temperature is 100 to 1
The method is carried out at 80 ° C., and this method is characterized in that there are few side reactions and it is possible to obtain uniformly added acid-modified polypropylene. On the other hand, in the case of the melting method, a Banbury mixer, a kneader, an extruder or the like is used, and the reaction is carried out at a temperature not lower than the melting point of the raw material resin and not higher than 300 ° C., the operation is simple and the reaction can be completed in a short time. . At the time of kneading, it is preferable that each resin component is uniformly mixed in advance in the form of powder or pellets by a device such as a tumbler or a Henschel mixer, but if necessary, the mixing is omitted and the kneading devices are separately provided. A method of supplying a fixed amount can also be used. The radical initiator used in the reaction can be appropriately selected from known ones, but organic peroxides are particularly preferable. Examples of the organic peroxide include benzoyl peroxide, dicumyl peroxide,
Lauroyl peroxide, 2,5-dimethyl-2,5
-Di (t-butylperoxy) -hexyne-3, di-t
-Butyl peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, cumene hydroperoxide and the like can be mentioned. Unreacted components (unsaturated carboxylic acid or its derivative,
In order to remove by-products such as radical initiators), their oligomers, decomposition products, etc., suction is performed by a vacuum pump with a vent line in the middle of the extruder or near the exit,
A method in which the reaction product is dissolved in an appropriate solvent and then precipitated to produce the reaction product can be used. Also, 60 ℃
It is also possible to perform vacuum treatment under heat treatment and melting at the above temperature. (2-2) Amino group-containing compound The amino group-containing compound having two or more primary amino groups in the molecule used for producing a modified polypropylene having a primary amino group is ethylenediamine, propylenediamine, tetramethylene. Diamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine,
Tetraethylenepentamine, iminobispropylamine, bis (hexamethylene) triamine, 1,3,6-
Aliphatic amines such as trisaminomethylhexane, trimethylhexamethylenediamine, bispropylenediamine, diethylaminopropylamine, and polyoxyalkylenepolyamine, menthenediamine, isophoronediamine, bis (4-amino-3-methylcyclohexyl) Methane and alicyclic amines such as 1,3-diaminocyclohexane, aliphatic aromatic amines such as metaxylylenediamine, o-, m-, p-phenylenediamine, 4,4′-diaminodiphenylmethane, diaminodiphenyl Sulfone, 2,4-diaminoanisole,
Aromatic amines such as 2,4-toluenediamine, 2,4-diaminodiphenylamine, and diaminodixylylsulfone. These can be used alone or in combination of two or more.

In the present invention, an amino group-containing compound having a structure with a large degree of freedom of molecular movement is used so that the primary amino group present in the resin composition can be oriented to the surface of the molded body in a short time. Particularly preferred is an aliphatic amino group-containing compound having at least one ether bond in the molecule. That is, an aliphatic primary diamine or triamine derived from polyethylene glycol, polypropylene glycol, or triol, which is generally called polyoxyalkylene polyamine, is particularly preferable. Among these amino group-containing compounds, those having a number average molecular weight of 10,000 or less can be preferably used. From the viewpoints of improving coating film adhesion, heat resistance, operability, etc., those having a number average molecular weight of 100 to 2,000 can be more preferably used. (2-3) Production of primary amino group-containing polypropylene resin
Method The modified polypropylene having a primary amino group comprises an acid-modified polypropylene to which an unsaturated carboxylic acid and / or a derivative thereof is added and an amino group-containing compound having two or more primary amino groups in the molecule, which have a melting point or higher. It can be manufactured by a method of heating and melting at a temperature of (1) to react (melting method) or a method of reacting in an organic solvent such as xylene (solution method).

The compounding ratio of the acid-modified polypropylene and the amino group-containing compound component for obtaining the modified polypropylene having a primary amino group used in the present invention is such that the carboxylic acid group and / or acid anhydride contained in the acid-modified polypropylene is mixed. With respect to the total number of moles m of the group, the melting reaction or the solution reaction is performed in such an amount that the total number of moles of the primary amino group contained in the amino group-containing compound component to be blended is at least 1 / m> 1. The primary amino group is introduced into the polypropylene molecular chain by a chemical bond, but in order to obtain practically sufficient coating film adhesion, the primary amino group content determined by the titration method is 0.5 × 10 ^-2 meq (CH ₃ ONa) /
It needs to be g (PP) or more.

In the solution method, it is preferable to use an aromatic solvent such as toluene or xylene as the organic solvent, and the reaction temperature can be 100 to 180 ° C. In this case, it is preferable to react at a compounding ratio of 1.5 <l / m <30. On the other hand, when the primary amino group is introduced into the polypropylene molecule by the melting method, it is preferable that l / m is in the range of 1.5 <l / m <10. When 1.5> l / m> 1, not only the amount of amino groups introduced is insufficient and the adhesion of the coating film is insufficient, but also the crosslinking reaction of polypropylene molecules becomes remarkable in the modification process, and the generated gel has a remarkable workability. Lower. On the other hand, when 1 / m> 10, not only is it uneconomical, but also unreacted amino group-containing compound remains in a large amount in the obtained modified polypropylene, which is not preferable. A particularly preferable compounding ratio is 2 <l / m <5.

In the case of the melting method, a Banbury mixer, a nib
Above the melting point of the raw material resin, using a feeder, extruder, etc.
The reaction can be performed at a temperature of ℃ or less. Melting method is operated
Is easy and can be pelletized in a short time
This is convenient. When kneading, each component should be
With a device like a tumbler or a Henschel mixer
It is preferable to mix evenly, but if necessary, mix
There is also a method of omitting the
Can be used. A multi-screw extruder is used as the kneading device.
Use can promote the reaction efficiently
Therefore, it is preferable. (3) Method for producing polypropylene resin composition containing amino group
Law The polypropylene resin composition of the present invention is a crystalline polypropylene.
By the above method for 0.1 to 95 parts by weight of pyrene (A)
Produced modified polypropylene having primary amino group
(B) is blended in an amount of 99.9 to 5 parts by weight, and the melting point of the raw material resin
It is manufactured by melt-kneading at a temperature below 300 ° C.
You can Also, acid-modified polypropylene, crystalline
Melts polypropylene and amino group-containing compounds simultaneously
It can also be manufactured by kneading. In addition,
Crystalline polypropylene is not only added to the manufacturing process
It can also be performed in the processing step. When kneading
Each ingredient is tumbler or Henschel in advance
It is preferable to mix uniformly with a device such as a mixer
However, if necessary, omit the mixing and use the extruder, Banbury mixer
Separately set on melt kneading equipment such as kisa and kneader.
A method of supplying a quantity can also be used. As a kneading device
Using a multi-screw extruder increases the dispersibility of each component
It is preferable because it can be obtained.

Further, crystalline polypropylene, unsaturated carboxylic acid or its derivative, and organic peroxide are supplied in the preceding stage of the extruder to prepare an acid-modified polypropylene, and further, an amino group-containing compound is added in the middle and subsequent stages of the extruder. By supplying the amino group-containing polypropylene resin composition, it is possible to directly obtain the amino group-containing polypropylene resin composition from the crystalline polypropylene in the extruder in one extrusion step, and this method is extremely useful from the viewpoint of production cost. In this case, in order to remove by-products such as unreacted components and decomposition products from the reaction product, suction is performed by a vacuum pump through a vent line in the middle of the extruder or near the outlet, or the reaction product is mixed with an appropriate solvent. Can be used after it is dissolved and then precipitated. (4) Reinforcing Material, Filler, Additive For the amino group-containing polypropylene resin composition of the present invention, if necessary, reinforcing material, filler, pigment, ultraviolet absorber, heat stabilizer, flame retardant, antioxidant. Agents, plasticizers, and the like can be added in the manufacturing process or the subsequent processing process as long as the physical properties of the resin are not impaired.

Specific examples of the reinforcing material and filler used in the amino group-containing polypropylene resin composition of the present invention include glass fiber, asbestos fiber, carbon fiber, silica fiber, silica / alumina fiber, alumina fiber, zirconia fiber, Reinforcing fibers such as boron nitride fiber, silicon nitride fiber, boron fiber, fumed silica, clay (aluminum silicate), glass beads, carbon black, quartz powder,
Inorganic fillers such as talc (magnesium silicate), titanium oxide, iron oxide, calcium carbonate and diatomaceous earth can be used.

The fibrous substance has an average fiber diameter of 5 to 30 μm,
Fibers having a fiber length of 30 to 50 μm can be used. In particular, glass fibers may be surface-treated with various coupling agents in order to improve interfacial adhesion and dispersibility with the polypropylene resin. The coupling agent usually contains a silane-based or titanium-based coupling agent. The inorganic filler may be used as it is without any treatment, but various silane coupling agents, higher fatty acids, for the purpose of improving the interfacial adhesion with the polypropylene resin and also improving the dispersibility.
The higher fatty acid ester, the higher fatty acid amide, the higher fatty acid salt or the one whose surface is treated with another surfactant can be used. The average particle size of the inorganic filler is preferably 5.0 μm or less, more preferably 5.0 μm or less, and the aspect ratio is 5 or more. A particularly preferred inorganic filler is talc.

The amount of the reinforcing material and the filler used is 0 to 40 parts by weight based on 100 parts by weight of the amino group-containing polypropylene resin composition of the present invention. 4 reinforcements and / or fillers
If the content exceeds 0 parts by weight, the impact resistance is significantly reduced, which is not preferable. A more preferred range is 5 to 30 parts by weight. These reinforcing materials and fillers can be used alone or in admixture of two or more. Particularly when the inorganic filler and the glass fiber are used in combination, the ratio of the inorganic filler and the glass fiber is 80 to 80% by weight with respect to the inorganic filler of 20 to 80% by weight.
20% is preferable.

[0022]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples below. Molding conditions and test methods for obtaining test samples from the amino group-containing polypropylene resin composition produced in each example are as follows. Primary amino in polypropylene resin composition containing amino group
Quantification of group content A primary amino group in the amino group-containing polypropylene resin composition was quantified by the following procedure. (1) The amino group-containing polypropylene resin composition was dissolved in hot xylene and reprecipitated in methanol for purification. After filtration, the purified sample was vacuum dried at 80 ° C. for 8 hours or more to remove the solvent. This reprecipitation purified sample is designated as a . (2) The amino group-containing polypropylene resin composition was dissolved in hot xylene, and after dissolution, 0.1N hydrochloric acid ethanol solution was gradually added dropwise until the solution became acidic, and the primary amino group was converted to amine hydrochloride. The polypropylene resin composition having an amine hydrochloride was purified by reprecipitation in methanol to obtain a solid sample. After recovery, vacuum drying was performed at 80 ° C. for 8 hours or more to remove the solvent. The polypropylene resin composition having this amine hydrochloride is designated as b . (3) Titrate each of sample a and sample b with 0.05 NNa methylate standard solution using phenolphthalene-ethanol solution as an indicator to obtain base equivalent to sample a (corresponding to amic acid content) and sample b The base equivalent (corresponding to the amic acid content + the amine hydrochloride content) was determined, and the primary amino group content in the amino group-containing polypropylene resin composition was determined from the difference in the amount of Na methylate used in both. The primary amino group content is the sodium methylate equivalent (meq (CH ₃ ONa) / g contained in 1 g of the amino group-containing polypropylene resin composition.
(PP)). Molding conditions for test piece for coating film adhesion evaluation The test piece for coating film adhesion evaluation was performed using an injection molding machine (Autoshot 50B, manufactured by FANUC Co., Ltd.) with a cylinder setting temperature of 230 ° C and a mold setting temperature of 60 ° C. Under the conditions, the cavity mold surface has a thickness of 50 μm of a polyimide film (trade name: Kapton, manufactured by Toray Industries, Inc., thermal conductivity: 2.5 × 10 ⁻⁴ cal /
cm ・ s ・ ℃) 100mm
A flat plate molded body of × 100 mm × 2 mm was obtained. Urethane-based paint adhesion test (1) Pretreatment, baking treatment A molded 2 mm thick flat plate surface was washed with ethanol and dried at 20 to 25 ° C for 1 hour or more,
Urethane paint (Retan PG60, Kansai Paint Co., Ltd.)
Spray coating (thickness: 30 to 40 μm). Then, after leaving it at 20 to 25 ° C. for 30 minutes, it was baked at 80 ° C. for 1 hour in a hot air circulation dryer. After finishing the baking treatment, the coating film was left for a further 24 hours, and then the coating film adhesion was evaluated by a cross-cut peeling test. (2) Cross- cut peeling test Using a cutter knife, 1 parallel line running straight on the coating film surface
100 grids were made by pulling each one at 1 mm intervals.
Cellophane adhesive tape (JIS-Z1522) was sufficiently pressure-bonded thereon, kept at about 30 ° with the coating film surface, and peeled off at once in front, and the state of the portion surrounded by cross-cuts was observed. The results were expressed as the number remaining / 100.

[0023]

Example 1 Addition amount of maleic anhydride is 0.33 wt%
(From titration with sodium methylate standard solution) and MFR (230 ° C., 2.16 kgf) 71 g
MFR of 25 g / 90 parts by weight of maleic anhydride-modified homopolypropylene (h-MPP) of / 10 min
10 min of crystalline homopolypropylene (M1700,
10 parts by weight of Asahi Kasei Co., Ltd., and further 3 parts by weight of Jeffamine D-230 (manufactured by Mitsuishi Texaco Chemical Co., Ltd.), which is an aliphatic primary diamine derived from polypropylene glycol, Set temperature 200
Twin screw extruder (L / D = 33.5 PCM-45 manufactured by Ikegai Tekko Co., Ltd.) at 250 ° C. and screw rotation speed of 250 rpm.
Were melt-kneaded using to obtain pellets of amino group-containing polypropylene resin composition. Using the injection molding machine, the obtained pellets were used to prepare a test piece under the conditions of a cylinder setting temperature of 230 ° C. and a mold setting temperature of 60 ° C., and the adhesion of the coating film was evaluated by the above test method. As shown in Table 1, the content of primary amino groups in the obtained polypropylene resin composition was 1.26 × 10 ⁻² meq (CH ₃ ONa) / g (PP).
Met. The paint adherence performance of the obtained molded product was extremely excellent.

[0024]

Example 2 90 parts by weight of h-MPP used in Example 1 was added with 10 parts by weight of M1700 and Jeffamine D-400 (Mitsuishi Texaco Chemical ( stock)
5 parts by weight of the product) was mixed and melt-kneaded in the same manner as in Example 1 to obtain pellets of an amino group-containing polypropylene resin composition. The content of primary amino groups in the obtained polypropylene resin is as shown in Table 1, and the coating performance of the obtained molded product was extremely excellent.

[0025]

Examples 3 and 4 h-MPP9 used in Example 1
10 parts by weight of M1700 per 0 parts by weight, Jeffermin EDR-148 which is an aliphatic primary diamine further derived from polyethylene glycol, and Jeffer which is an aliphatic primary triamine derived from triol. Min T-403 (all manufactured by Mitsuishi Texaco Chemical Co., Ltd.) was blended in the blending amounts shown in Table 1, and Example 1 was used.
Pellets of the amino group-containing polypropylene resin composition were obtained by melt-kneading in the same manner as. The content of primary amino groups in the obtained polypropylene resin composition is as shown in Table 1, and the coating performance of the obtained molded article was extremely excellent.

[0026]

Example 5 To 90 parts by weight of h-MPP used in Example 1, 10 parts by weight of M1700 and 3 parts by weight of hexamethylenediamine were added, and the mixture was melt-kneaded in the same manner as in Example 1 to give an amino group. Pellets containing polypropylene resin were obtained. The content of primary amino groups in the obtained polypropylene resin composition was 2.52 × 10 ^-2 meq (CH
₃ ONa) / g (PP). The coating performance of the obtained molded product was excellent.

[0027]

Examples 6 and 7 The amount of maleic anhydride added was 0.4.
5 wt% and MFR 55 g / 10 min maleic anhydride-modified block polypropylene (b-MP
P), crystalline block polypropylene with MFR of 25 g / 10 min (M8749, Asahi Kasei Corporation)
Manufactured) and Jeffamine D-400 were blended in the blending amounts shown in Table 1 and melt-kneaded in the same manner as in Example 1 to obtain pellets of an amino group-containing polypropylene resin composition.
The content of primary amino groups in the obtained polypropylene resin was as shown in Table 1, respectively. The coating performance of the obtained molded articles was extremely excellent.

[0028]

Comparative Examples 1 and 2 h-MP used in Examples 1 and 2
Table 2 shows the coating performance of the molded articles obtained from the P and b-MPP pellets.

[0029]

COMPARATIVE EXAMPLE 3 10 parts by weight of M1700 and 1 part by weight of Jeffamine D-400 were mixed with 90 parts by weight of h-MPP used in Example 1 and melt-kneaded in the same manner as in Example 1. Pellets of the amino group-containing polypropylene resin composition were obtained. The content of primary amino groups in the obtained polypropylene resin is as shown in Table 2, and the obtained molded product could not obtain sufficient paint adhesion performance.

[0030]

[Comparative Example 4] The amount of maleic anhydride added was 0.10 wt%
H-MPP with MFR of 60 g / 10 min
10 parts by weight of M1700 and 1 part by weight of Jeffamine D-400 were mixed with 90 parts by weight, and the mixture was melt-kneaded in the same manner as in Example 1 to obtain pellets of an amino group-containing polypropylene resin composition. The content of primary amino groups in the obtained polypropylene resin is as shown in Table 2, and the obtained molded product could not obtain sufficient paint adhesion performance.

[0031]

Comparative Example 5 To 40 parts by weight of b-MPP used in Example 6, 60 parts by weight of M8749 and 2.5 parts by weight of Jeffamine D-400 were blended and melt-kneaded in the same manner as in Example 1. Thus, pellets of amino group-containing polypropylene resin composition were obtained. The content of primary amino groups in the obtained polypropylene resin is as shown in Table 2, and the obtained molded product could not obtain sufficient paint adhesion performance.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

The amino group-containing polypropylene resin composition according to the present invention is molded by using a mold in which the surface of the mold is covered with a heat insulating material having a high affinity for amino groups (Japanese Patent Application No. 2000-242242). By molding using HEI 5-042345), the surface of the molded product can be directly coated on the molded product without any modification treatment, and it has a practically sufficient paint adhesion strength and is practically sufficient. Since it has excellent mechanical strength, it is useful for automobile parts, housings for home electric appliances, daily sundries, and the like. Also, simplification of painting process, improvement of working environment,
It is possible to reduce production costs.

Claims (3)

[Claims] 1. The crystalline polypropylene (A) is 0.1 to 10.
A polypropylene resin composition comprising 95 parts by weight and 99.9 to 5 parts by weight of a modified polypropylene (B) having a primary amino group, wherein the resin composition has a primary amino group content of 0.5 × 10 ^−. An amino group-containing polypropylene resin composition containing ² meq (CH ₃ ONa) / g (PP) or more. 2. A modified polypropylene (B) having a primary amino group is an acid-modified polypropylene having an unsaturated carboxylic acid and / or a derivative thereof added thereto, and has at least one ether bond and at least two primary groups in the molecule. The polypropylene resin composition according to claim 1, which is a modified polypropylene obtained by reacting an amino group-containing compound having an amino group. 3. A coated article having a paint adhered to the polypropylene resin composition according to claim 1.