JPH04359026A - Molding and coated molding - Google Patents

Abstract

PURPOSE:To provide a molding exerting favorable coating adhesivity even when directly coated without preliminary surface-modifying treatment such as priming or plasma treatment. CONSTITUTION:The objective molding (and directly coated molding therefrom) obtained from a resin composition formed by incorporating (A) 100 pts.wt. of a vinylsilane-modified olefinic resin with (B) 0.01-40 pts.wt. of a copolymer of ethylene and a hydroxyl group-contg. unsaturated compound (and furthermore, where appropriate, (C) 1-200 pts.wt. of an elastomer component).

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article made of a vinylsilane-modified propylene resin material suitable for coating the surface thereof, and a coated molded article whose surface is coated. More specifically, molded bodies formed from resin compositions comprising a vinylsilane-modified propylene resin and a copolymer of ethylene and an unsaturated compound containing a hydroxyl group, and resin compositions formed by further adding an elastomer component to each of these components. The present invention relates to molded bodies formed from such molded bodies, and coated molded bodies in which the surfaces of these molded bodies are directly coated.

0002

BACKGROUND OF THE INVENTION Conventionally, propylene resins have been known to have extremely poor paint adhesion and poor paintability due to the absence of polar groups in their structure and high crystallinity. Therefore, in order to improve this poor adhesion,
The surface of the propylene resin has been modified by applying a primer or plasma treatment in advance to improve its paintability before applying the paint.

0003

[Problems to be Solved by the Invention] However, such coating methods have conventionally had the following problems. In other words, the primer application method requires the use of expensive primers,
There are drawbacks such as higher painting costs due to the increased number of painting steps, but there are also disadvantages such as the need to volatilize the solvent in the primer, which creates a poor work environment and poses a risk of fire, making it safer. There were also problems with sexuality. On the other hand, in the plasma processing method, since a high degree of vacuum is required, expensive equipment must be installed, and furthermore, since it is a batch method, an increase in cost cannot be avoided. Furthermore, the surface after plasma treatment is unstable, and the adhesion of the paint decreases when it comes into contact with foreign matter, which can lead to variations in coating film performance, making handling very inconvenient. Therefore, if such primer application and plasma treatment processes could be omitted, it would be possible to simplify the painting process, improve the working environment, and reduce costs. Many studies have been conducted to try to improve these problems. However, in the end, this goal has not yet been achieved, and with propylene resin materials, such primer application and plasma treatment cannot be omitted, and there are cases where painting is applied after such treatment. many.

0004

[Means to solve the problem]

[Summary of the Invention] As a result of extensive research in view of the above problems, the present inventors have found that the above problems can be solved by using a specific resin composition for the object to be coated. As a result, the present invention has been completed. That is, the molded article of the present invention contains a vinylsilane-modified propylene resin, and 0 parts by weight of a copolymer of ethylene and a hydroxyl group-containing unsaturated compound with respect to 100 parts by weight of the vinylsilane-modified propylene resin.
．． 01 to 40 parts by weight (plus elastomer component 1 to 40 parts by weight)
200 parts by weight of the resin composition. Further, the coated molded body, which is another invention of the present invention, contains a vinyl silane-modified propylene resin, based on 100 parts by weight of the vinyl silane-modified propylene resin.
The copolymer of ethylene and a hydroxyl group-containing unsaturated compound is 0.
01 to 40 parts by weight (plus elastomer component 1 to 2)
00 parts by weight) is characterized in that a paint is directly applied onto the surface of a molded article formed from a resin composition.

[Detailed Description of the Invention] [I] Resin Composition (1) Constituent Components The resin composition forming the molded article of the present invention is basically formed from the constituent components shown below. (a) Component: Vinylsilane-modified propylene resin The vinylsilane-modified propylene resin used in the present invention is a propylene resin containing an alkoxysilane group in the molecule, and the polymers are crosslinked with each other by the alkoxysilane group. It is. A preferred example of the vinyl silane-modified propylene resin is a propylene resin modified with a vinyl silane compound. Specifically, a vinylsilane compound such as vinyltrimethoxysilane or γ-methacroyloxypropyltrimethoxysilane is graft copolymerized onto a propylene polymer. These vinylsilane-modified propylene polymers are described in detail in, for example, Japanese Patent Publication No. 48-1711, Japanese Patent Application Publication No. 59-36115, and Japanese Patent Application Publication No. 55-9611,
It is also available on the market.

[0006] Vinylsilane-modified propylene resins undergo a crosslinking reaction easily in water using a silanol condensation catalyst such as dibutyltin dilaurate. The vinylsilane-modified propylene resin used in the present invention can be easily water-crosslinked by placing the obtained molded article in water or an atmosphere containing moisture. Depending on the purpose, the vinylsilane-modified propylene resin can be used alone or as a mixture with a propylene resin. The content is preferably 30% by weight or more, particularly preferably 30 to 90% by weight. The propylene resin used above is a propylene homopolymer, a random or block copolymer of propylene and about 30% by weight or less of other α-olefins, such as ethylene, butene-1, etc., or a mixture thereof. etc., and the bending elastic modulus measured in accordance with JIS-K7203 is 1,000 to 20,000k.
g/cm2, preferably 2,000-18,000k
g/cm2, particularly preferably 3,000 to 15,00
0 kg/cm2 of resin can be mentioned. Also,
The melt flow rate (MFR) of this copolymer resin is not particularly limited, but the value measured according to ASTM-D1238 is usually 0.01 to 200 g/10 minutes, preferably 0.1 to 100 g/10 minutes. Optimally, it should be within minutes. Among these propylene resins, it is preferable to use propylene/ethylene block copolymers. These resins can be appropriately selected from commercially available products.

Component (b): Copolymer of ethylene and unsaturated compound containing hydroxyl group The copolymer of ethylene and unsaturated compound containing hydroxyl group is:
For example, it refers to a polymer in which ethylene and 2-hydroxyethyl methacrylate are copolymerized randomly or at certain intervals, but from a structural standpoint, it refers to a polymer with branched or linear carbon chains. Refers to all compounds having a structure in which unsaturated compounds containing hydroxyl groups are copolymerized irregularly or regularly. Specifically, the content of the hydroxyl group-containing unsaturated compound is 0.1 to 50% by weight, preferably 0.5 to 45% by weight, particularly preferably 1 to 40% by weight, and the molecular weight is 200 to 200. 000, preferably 500 to 150,000, particularly preferably 800
Polymers that are liquid, semi-solid, and solid at room temperature of ~100,000 are included. A copolymer of ethylene and an unsaturated compound containing a hydroxyl group can be produced using ethylene and an unsaturated compound containing a hydroxyl group as raw materials by a well-known method such as a high-pressure radical polymerization method. In the case of high-pressure radical polymerization,
Ethylene, a hydroxyl group-containing unsaturated compound, and a radical reaction initiator are heated, for example, at a pressure of 1000 to 3000 atm and a temperature of 9
In the reaction zone maintained at 0 to 280°C, the ratio of ethylene:hydroxyl group-containing unsaturated compound is 1:0.0001 to 1:0.0.
2, converting 3 to 20% of the ethylene into the copolymer, and continuously withdrawing the copolymer from the reaction zone.

[0008] Examples of the hydroxyl group-containing unsaturated compound herein include 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, poly(ethylene glycol) monomethacrylate, and the like. In addition to ethylene and hydroxyl group-containing unsaturated compound components, as a third copolymer component, unsaturated carboxylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and methyl methacrylate; styrene, α-methylstyrene, vinyl toluene, etc. Vinyl aromatic compounds: Nitrile compounds such as acrylonitrile and methacrylonitrile; Vinyl pyridines such as 2-vinylpyridine and 4-vinylpyridine; Vinyl ethers such as methyl vinyl ether and 2-chloroethyl vinyl ether; Halogens such as vinyl chloride and vinyl bromide. It is also possible to use it as a ternary or multicomponent copolymer using vinyl chloride: vinyl ester such as vinyl acetate: acrylamide. These copolymers can be used alone or as a mixture of a plurality of them.

Additional Components The composition of the present invention may contain the following additional components in addition to the above-mentioned essential components to the extent that the effects of the present invention are not significantly impaired.

[0010] Examples of additional components include polyolefins other than the above-mentioned propylene resins, specifically polyethylene resins such as low-pressure polyethylene, medium-pressure polyethylene, high-pressure polyethylene, and linear low-density polyethylene;
Stereoregular poly-1-butene, stereoregular poly-4-methylpentene-1, etc., olefin-based, styrene-based, acrylic-based elastomers, inorganic fillers, specifically natural silica such as quartz, wet methods, Synthetic silica manufactured by dry process, natural silicates such as kaolin, mica, talc, asbestos, synthetic silicates such as calcium silicate, aluminum silicate, metal hydroxides such as magnesium hydroxide, aluminum hydroxide, alumina, titania, etc. metal acid compounds such as calcium carbonate, aluminum, bronze and other metal powders, carbon black, glass fiber, carbon fiber,
Whiskers include potassium titanate, calcium sulfate, zinc oxide, silicon nitride, sapphire, beryllia, boron carbide, and silicon carbide. In addition, other additives, specifically colorants, stabilizers, dispersion aids, molecular weight regulators, crosslinking agents, nucleating agents, etc. can be mentioned.

Among these additional components, the above-mentioned olefin elastomer is advantageous because it allows adjustment of rigidity, impact resistance, etc. Examples of such olefin elastomers include ethylene, propylene,
- copolymers of α-olefins such as butene and 1-hexene, or copolymers of these and nonconjugated dienes. The copolymer has an initial elastic modulus of 400 kg/cm2 or less, preferably 200 kg/cm2 or less, particularly preferably 100 kg/cm2, as measured in accordance with JIS-K6301.
/cm2 or less, preferably an amorphous or low crystalline copolymer.

[0012] Specific examples of the above-mentioned non-conjugated diene include:
Dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, dicyclooctadiene, methylenenorbornene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 5-methylene-2-norbornene, 5-methyl- 1,4-hexadiene, 7-methyl-
1,6-octadiene and the like can be mentioned.

These olefin elastomers have 1
Mooney viscosity ML1+4 measured at 00℃ is usually 1
-200, preferably 5-150, particularly preferably 7-
100 range.

Among these olefin elastomers, ethylene elastomers are preferred in terms of quality and stability. Specifically, ethylene/propylene copolymer rubber (E
PM), ethylene/1-butene copolymer rubber, ethylene/
Propylene/1-butene copolymer rubber, ethylene/propylene/non-conjugated diene copolymer rubber (EPDM), ethylene/1-butene/non-conjugated diene copolymer rubber, ethylene/propylene/1-butene/non-conjugated diene copolymer rubber etc. Among the ethylene-based elastomers, EPM is particularly preferred because the surface of the molded product is less likely to be roughened and the coated surface is beautifully finished. However, it is generally known that elastomer formulations tend to improve paint adhesion, but in the present invention, even without elastomer formulations, direct coating has good paint adhesion, and the predicted It was a difficult and unexpected thing to do.

(2) Quantitative ratio The quantitative ratio of the above-mentioned components constituting the resin composition used in the present invention is usually 100 parts by weight of the vinylsilane-modified propylene resin, ethylene and the hydroxyl group-containing unsaturated compound. 0.01 to 40 parts by weight, preferably 0.05 to 35 parts by weight, particularly preferably 0.1 to 35 parts by weight
It is within the range of 30 parts by weight. If the amount of the copolymer of ethylene and a hydroxyl group-containing unsaturated compound is less than the above range, it is not preferable because the reproducibility of the paint adhesion may be poor or the adhesion strength of the paint may be weak. On the other hand, if the above range is exceeded, the amount of the expensive polymer added increases, resulting in a high cost as a resin composition, and the polymer tends to delaminate or bleed out, reducing the adhesion of the paint. It is not desirable to do so. Further, it is convenient to further blend an elastomer component into the resin composition having the above-mentioned blending ratio of the constituent components, since rigidity, impact resistance, etc. can be adjusted. Therefore, from the viewpoint of mechanical strength, the elastomer component is 1 part propylene resin.
1 to 200 parts by weight, preferably 5 to 200 parts by weight
It is preferable to use 150 parts by weight, particularly preferably 10 to 100 parts by weight.

(3) Blending By mixing the above-mentioned components, a resin composition serving as a raw material for the resin molded article of the present invention is produced. The mixing order of these components is not particularly limited, and any method may be used, such as a method of mixing the above-mentioned components at the same time, a method of mixing any two components in advance, and then mixing the remaining components. As a mixing method, any conventionally known kneading machine can be used, such as a Brabender plastograph, a single-screw or twin-screw extruder, a high-power screw kneader, a Banbury mixer, a kneader, and a roll.

[II] Molded object The molded object of the present invention can be obtained by molding the resin composition described above using various molding methods. Molding can be carried out by conventional methods. That is, any molding method such as injection molding, compression molding, extrusion molding (sheet molding, blow molding), etc. may be used. It is particularly effective for molded articles injection molded into complex shapes.

[III] Crosslinking Treatment The molded product formed here can be crosslinked with water by immersing it in water or hot water, exposing it to a steam atmosphere, or packaging it in a material containing water. However, in principle, any method may be used as long as the molded product comes into contact with moisture; for example, it may be left in the atmosphere.

[IV] Coating As the coating method for forming the coated molded article of the present invention, it is possible to adopt a process that excludes surface modification processes such as primer application and plasma treatment from the conventional painting process. can. That is, a coating material is applied to a molded article obtained by forming and processing the resin composition either directly or after degreasing treatment if necessary. In the present invention, "directly painted" means that the paint is applied without applying the conventional primer application or plasma treatment.
Unless it deviates from the technical idea of the present invention, it is not excluded that some kind of surface treatment be performed before applying the paint. One example of such surface treatment is degreasing treatment. Such degreasing is a normal operation that is generally performed just before applying paint, and it removes hand grime that inevitably adheres to the surface of the molded product during the process from molding the resin composition to painting. It is possible to wash and remove machine oil, etc. Specifically, there are cleaning methods using organic solvents or their vapors, water, steam, acids, alkaline aqueous solutions, surfactant aqueous solutions, etc. Among these, cleaning methods using organic solvent vapors and various aqueous solutions are preferably used. In addition, methods of applying paint include spraying, brushing, and roller application.
Either method can be adopted.

[0020] Paints that can be used in the main painting process include commonly used paints, such as acrylic paints, epoxy paints, polyester paints,
Urethane paints, alkyd paints, etc. can be used. Among these, acrylic paints and urethane paints are preferred, and acrylic paints are particularly preferred.

[V] Painted resin molded body The paint is generally applied to the molded body coated in this manner at a concentration of 10 to 1
The coating is applied to a thickness of 00 μm, preferably 20 to 70 μm, and the coating is strongly adhered, so it can be applied to various industrial parts such as automobile bumpers, mudguards, side moldings, wheel caps, spoilers, etc. Automotive exterior parts, instrument panels, levers, knobs, interior linings and other automotive interior parts, pots, vacuum cleaners, washing machines, refrigerators, lighting equipment, audio equipment and other electrical products, color boxes, storage cases and other miscellaneous goods. It can be used as a product.

[0022]

[Examples] The present invention will be explained in more detail with reference to Examples and Comparative Examples below. The molding conditions and test methods for obtaining test samples from the resin compositions produced in each example are as shown below. In addition, "part" in the example
is parts by weight. (1) Compounding components <Vinylsilane modified olefin resin: (a) component>S
i-ized PP (1): ethylene content 13.8% by weight, JI
Flexural modulus measured in accordance with S-K7203 is 13,
000kg/cm2, MFR measured in accordance with ASTM-D1238 is 11g/10min, and the silane compound content is 2.2% by weight. Vinyltrimethoxysilane graft-propylene-ethylene block copolymer (
Product trademark manufactured by Mitsubishi Yuka Co., Ltd. "Linklon
MFR measured according to STM-D1238 is 14g
/10 minutes, vinyltrimethoxysilane graft polypropylene copolymer with a silane compound content of 2.5% by weight (Mitsubishi Yuka Co., Ltd. product trademark "Linklon XPM80")
0H”) Block PP: Ethylene content is 4% by weight, JIS-K7
Flexural modulus measured in accordance with 203 is 14,000k
A propylene-ethylene block copolymer with a weight ratio of 60 g/cm2 and an MFR of 60 g/10 min as measured in accordance with ASTM-D1238. Homo PP: Flexural modulus measured in accordance with JIS-K7203 is 13,000 kg/cm2, and ASTM-
Polypropylene with an MFR of 25 g/10 min measured according to D1238.

<Copolymer of ethylene and hydroxyl group-containing unsaturated compound: component (b)> EHM (1) 2-hydroxyethyl methacrylate content 10% by weight, molecular weight 54,000, obtained by high-pressure radical polymerization method. ethylene/2-hydroxyethyl methacrylate copolymer. EHM (2) Ethylene 2- 2-hydroxyethyl methacrylate content 10% by weight, methyl acrylate content 10% by weight, molecular weight 46,000, obtained by high-pressure radical polymerization method.
Hydroxyethyl methacrylate/methyl acrylate copolymer. EHM (3) Ethylene 2- 2-hydroxyethyl methacrylate content 10% by weight, methyl acrylate content 10% by weight, molecular weight 32,000, obtained by high-pressure radical polymerization method.
Hydroxyethyl methacrylate/methyl acrylate copolymer. EHM (4) Ethylene/2-hydroxyethyl methacrylate copolymer with a 2-hydroxyethyl methacrylate content of 35% by weight and a molecular weight of 2,300, obtained by high-pressure radical polymerization.

<Elastomer component> EPM (1) Ethylene-propylene copolymer rubber having a Mooney viscosity ML1+4 (100°C) of 70 and a specific gravity of 0.86. EPM (2) Ethylene-propylene copolymer rubber having a Mooney viscosity ML1+4 (100°C) of 24 and a specific gravity of 0.86. EPDM Ethylene-propylene-ethylidenenorbornene copolymer rubber having a Mooney viscosity ML1+4 (100°C) of 47 and a specific gravity of 0.86.

(2) Evaluation <Molding conditions> Injection molding machine manufactured by Molding Machine Meiki Seisakusho M40A-SJ Molding temperature 230°C Molded product flat plate (65 mm x 65 mm x 2 mm) Three-point flexural modulus test piece (90 mm x 10 mm x 4mm)
Flexural modulus was measured in accordance with JIS K-7203. MFR Measured in accordance with ASTM D-1238.

<Painting> Paint Painting was carried out using a one-component acrylic paint and a one-component urethane paint. Coating method Each paint was prepared and spray coated using an air spray gun so that the coating thickness was approximately 40 μm in the grid test and approximately 100 μm in the peel strength test. after that,
Acrylic paints were baked at 100°C for 60 minutes, and urethane paints were baked at 120°C for 60 minutes.

<Evaluation of paint adhesion> Cross-cut test Using a single-edged razor, 11 vertical and horizontal parallel lines perpendicular to the surface of the test piece were drawn at 2 mm intervals to form 100 cross-cuts. On top of that, apply cellophane adhesive tape (JIS Z152
2) was sufficiently crimped, maintained at about 30 degrees to the coating surface, and peeled off at once toward the viewer.The state of the area surrounded by the grid was observed, and the number of grids that did not peel off was recorded. After treating the upper half of the peel strength test piece to prevent paint from adhering, each paint was applied to a film thickness of 100 μm and baked and dried. Apply cellophane adhesive tape (e.g.
Apply a Nichiban product (width 24 mm) to the entire surface and make a 1 cm wide cut vertically reaching the base material. The side to which the coating film was not attached was peeled off by hand, and the sample was attached to a tensile testing machine and the load was recorded when the sample was peeled off in a 180 degree direction at a speed of 50 mm/min. In addition, when the coating film was broken, it was described as broken.

<Crosslinking treatment> The molded body was placed in hot water at 95°C for 16 days.
Soaked for an hour.

<Evaluation of cross-linked product> Gel fraction The cross-linked sample was extracted using a Soxhlet type extractor at boiling point temperature for about 24 hours using xylene as a solvent, and the weight of the extracted residue was expressed as a percentage according to the following formula. shall be taken as a thing.

[Equation 1] Heating and pressing deformation rate A sheet with a thickness of 2 mm is formed, and the length of this sheet is 10 mm.
, cut out a test piece with a width of 10 mm. This test piece was
The test piece was placed between pressure plates in a silicone oil bath at 0.degree. C., a predetermined load (3 kg) was placed on the test piece, and pressure was applied to the test piece for 1 hour. The amount of change in the thickness of the test piece is determined using a dial gauge, and the heating and pressing deformation rate (%) is calculated using the following formula.

[Math 2]

Examples 1 to 11 and Comparative Examples 1 to 5 Production of resin moldings The components shown in Tables 1 and 2 were blended and melt-kneaded at 200° C. using a twin-screw extruder to form pellets. Using this pellet, a flat plate and a test piece for three-point bending modulus measurement were injection molded. Coating of resin molded body The flat plate formed by the above resin molded body was degreased with trichloroethane vapor for 30 seconds, and then a paint was applied using an air gun. After baking and drying, 4
A grid test was conducted after leaving the sample at room temperature for 8 hours. Tables 1 and 2 show the results of the elastic modulus and paint adhesion of the resin compositions obtained.

[0031]

[Table 1]

[0032]

[Table 2]

In the composition shown in Comparative Example 5,
It was too soft to measure the flexural modulus using the measurement method based on JIS-K7203. Furthermore, during painting, the flat plate of the test piece was severely deformed during baking and drying after coating, and the surface of the flat plate also became uneven, making it impossible to evaluate. In addition, in Example 2 and Comparative Example 2, the results were evaluated using the same method except that the obtained molded bodies were crosslinked.
It can be seen that the heat-pressure deformation rate is reduced by the crosslinking treatment, and not only is the heat resistance improved, but especially in Example 2, the strength of paint adhesion is also further improved.

[0034]

Effects of the Invention The molded bodies and painted molded bodies of the present invention can be produced by using specific components in the resin composition forming the molded bodies. Contrary to the common sense that ``it is impossible to do this,'' the molded body exhibits good paint adhesion even when the paint is applied directly to the molded body without prior surface modification treatment such as primer coating or plasma treatment. It is something that can be done. In addition, even if additives such as commonly used resin light stabilizers, antioxidants, and lubricants are added to the resin composition, the paint adhesion strength will not decrease and good paint adhesion will be achieved. It is extremely useful industrially.

Claims (4)

[Claims] Claim 1: Vinylsilane-modified propylene resin,
It is characterized by being formed from a resin composition comprising 0.01 to 40 parts by weight of a copolymer of ethylene and a hydroxyl group-containing unsaturated compound to 100 parts by weight of the vinylsilane-modified propylene resin. A molded object. Claim 2: Vinylsilane-modified propylene resin,
For 100 parts by weight of the vinylsilane-modified propylene resin, 0.01 to 40 parts by weight of a copolymer of ethylene and a hydroxyl group-containing unsaturated compound and 1 to 40 parts by weight of an elastomer component.
A molded article characterized in that it is formed from a resin composition containing 200 parts by weight. Claim 3: Vinyl silane-modified propylene resin,
On the surface of a molded body formed from a resin composition in which 0.01 to 40 parts by weight of a copolymer of ethylene and a hydroxyl group-containing unsaturated compound is blended with 100 parts by weight of the vinylsilane-modified propylene resin, A molded object characterized by being directly coated with paint. Claim 4: Vinylsilane-modified propylene resin;
For 100 parts by weight of the vinylsilane-modified propylene resin, 0.01 to 40 parts by weight of a copolymer of ethylene and a hydroxyl group-containing unsaturated compound and 1 to 40 parts by weight of an elastomer component.
A coated molded article, characterized in that the paint is directly applied to the surface of a molded article formed from a resin composition containing 200 parts by weight.