JPH06155503A - Polyolefin resin injection molded piece and its molding method - Google Patents

Abstract

PURPOSE:To omit a pretreatment before coating, such as a trichloroethane cleaning and a primer treatment, and to improve a coating adhesion, a surface smoothness, and a clarity by a method wherein a concentration ratio of oxygen, carbon, and nitrogen on an uppermost surface of a molded piece is specified, and a 60 deg. glossiness on the surface is a specific value or more. CONSTITUTION:In a resin injection molded piece made of a functional polyolefin resin bonded with at least one kind of functional group selected out of hydroxyl group, amino group, carboxyl group, anhydrous carboxyl group, and epoxy group, (CO+CN)/CC is 0.005-0.300 on the uppermost surface of the molded piece where an oxygen concentration is CO, a carbon concentration is CC, and a nitrogen concentration is CN, and a 60 deg. glossiness (ASTM-D523) on the surface is at least 60%. If the concentration ratio of the specific elements on the uppermost surface of the molded piece is lower than the lower limit, an ideal coating adhesion cannot be obtained. If it is larger than the upper limit, a surface layer may be released, or a weatherability may be deteriorated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin resin injection-molded article excellent in paintability, surface smoothness, and sharpness after painting, and a method for producing the same. More specifically, a specific surface composition comprising a functionalized polyolefin-based resin and a polyolefin-based resin, which shows excellent coating adhesion without performing trichloroethane treatment and primer treatment, and has excellent surface smoothness after coating. With respect to the injection-molded article and the manufacturing method thereof, the injection-molded article of the present invention can be effectively used for automobile exterior parts and other parts to be painted.

[0002]

2. Description of the Related Art Polyolefin resins are widely used as general-purpose resins because they are lightweight and inexpensive in addition to being excellent in moldability, solvent resistance and chemical resistance. Also,
Regarding the drawback of insufficient mechanical properties represented by rigidity and impact resistance, filler / elastomer reinforcement described in JP-A-4-153243 or the like, or JP-A-4-9335.
Techniques for improving the level of engineering plastics by polymer alloying and the like described in No. 3 and the like are disclosed, and application to a wider range of applications is expected.

However, since the polyolefin resin does not have an active functional group, the appearance and decorativeness represented by the coating property is extremely poor, and in a molded product requiring coating,
In general, sufficient coating adhesion strength cannot be obtained unless surface cleaning with a primer such as chlorinated polyolefin is performed in addition to degreasing and cleaning with a halogenated hydrocarbon such as trichloroethane.

Further, the above-mentioned primer treatment not only improves the coating adhesion, but also fills the fine irregularities on the surface of the molded product, so that even if a thin coating film is applied, the so-called class A is excellent. It also has the function of obtaining the painted surface of. Therefore, even if the coating adhesion is improved simply by using a composition that does not require degreasing and cleaning with a halogenated hydrocarbon such as trichloroethane and a surface treatment with a primer such as a chlorinated polyolefin, which has been conventionally performed, even if the coating adhesion of the surface after coating is improved, The sharpness is inferior to that of the primer-treated one.

Conventionally, such degreasing cleaning and primer treatment have been taken up as problems such as an increase in the number of steps and an increase in processing cost. In recent years, however, environmental problems due to halogenated hydrocarbons have been added, and in the future. It is most desirable to omit these steps. As a method for improving the paintability of the polyolefin resin, a polyolefin resin composition having improved paintability, a pretreatment method for improving the paintability of the polyolefin, and a paint having good adhesion to polyolefin are disclosed. However, they are not sufficient because they do not exhibit sufficient effects, lose the excellent properties of the polyolefin-based resin, or take into consideration the sharpness after painting.

For example, as a composition having improved coatability,
The polypropylene-based polymer composition grafted with the reactive compound having a hydroxyl group described in JP-B-4-25292 is
In some cases, excellent coating adhesion is exhibited, but depending on the molding method, the coating properties may be reduced due to the reduction of the functional groups on the outermost surface, which is not sufficient. In addition, JP-A-4-26
The polypropylene resin composition in which the specific elastomer described in No. 1450 is mixed is inadequate because sufficient paintability cannot be obtained without the primer treatment. Further, the thermoplastic resin composition comprising polypropylene, polyamide and a modifier described in JP-A-4-227957 has a high specific gravity although the coatability can be improved, and the low specific gravity which is a characteristic of polyolefin cannot be utilized. Further, the methods described in JP-B-4-25292, JP-A-4-261450 and JP-A-4-227957 do not take into consideration the sharpness after coating.

As a pretreatment method for improving the coatability, chromic acid treatment, sandblast treatment, flame treatment, corona discharge treatment, plasma treatment and the like can be mentioned, but not only the coatability is not sufficient, but the number of treatment steps is increased. It becomes complicated and is not preferable. Similarly, JP-A-4-266935.
The formation of the polyhydroxyethyl acrylate polymer film on the surface of the molded article described in No. 1 is also not preferable because the treatment process is complicated.

As a paint having good adhesion to polyolefins, there may be mentioned paints containing a chlorinated polyolefin as described in JP-A-4-132783, but these have a poor weather resistance of the coating film itself, and are therefore insufficient. Not a solution.

[0009]

As described above, as a method for obtaining excellent coating adhesion without losing the excellent properties of polyolefin and obtaining excellent surface gloss with a thin coating film, Although the current method using trichloroethane washing and primer treatment is optimal, the trichloroethane washing and primer treatment are not appropriate in consideration of problems such as increased process steps and environmental problems. An object of the present invention is to provide an injection-molded article which has sufficient coating adhesion without the above-mentioned pretreatment and has excellent surface smoothness and sharpness after coating.

[0010]

Means for Solving the Problems In the molded product of a functionalized polyolefin-based resin having a functional group bonded in the molecule and a resin composed of the polyolefin-based resin, the present inventors derive from the concentration of the functional group on the outermost surface. The inventors have found that when the element concentration is a specific value or more, it exhibits excellent coatability, and that a molded article having a good gloss on the surface of the molded article has excellent image clarity after coating, and arrived at the invention described below.

That is, the present invention relates to a resin comprising a functionalized polyolefin resin and a polyolefin resin to which at least one functional group selected from a hydroxyl group, an amino group, a carboxylic acid group, a carboxylic acid anhydride group and an epoxy group is bonded. In the injection molded product of (1), (C _O + C _N ) / C _C is 0 for oxygen concentration (C _O ), carbon concentration (C _C ), and nitrogen concentration (C _N ) on the outermost surface of the molded product. 0.005-0.30
0, and (2) 60 ° gloss gloss (ASTM
-D523) is at least 60% or more, and a polyolefin resin injection-molded article, and at least one functional group selected from a hydroxyl group, an amino group, a carboxylic acid group, a carboxylic acid anhydride group, and an epoxy group. In injection-molding a resin composed of 5 to 100% by weight of a functionalized polyolefin-based resin and 95 to 0% by weight of a polyolefin-based resin bonded to each other, the surface of a mold on which the injection-molded article is to be formed is preheated and then injection-molded. The present invention relates to a method for molding a polyolefin-based resin injection-molded article, which is characterized in that it is performed.

The details will be described below. Polyolefin Resin The polyolefin resin used in the present invention is, for example, (1) high-pressure ethylene homopolymer, high-pressure ethylene-α olefin random copolymer, etc., and has a density at 23 ° C. of 0.88 to 0. 0.94 g / cm ³ , 190 ° C
The melt index under a load of 2.16 kg is 0.
Low density polyethylene, 1-100 dg / min, (2)
1. Low-pressure ethylene homopolymer, low-pressure ethylene-α-olefin random copolymer, etc., having a density at 23 ° C. of 0.94 to 0.98 g / cm ³ and at 190 ° C.
Melt index under load of 16 kg is 0.01-100
High density polyethylene having a dg / min of (3) low pressure method ethylene-α olefin random copolymer having a density at 23 ° C. of 0.88 to 0.94 g / cm ³ , 190 ° C.
The melt index under a load of 2.16 kg is 0.
1 to 100 dg / min of linear low-density polyethylene, (4) propylene homopolymer, propylene-ethylene random copolymer, propylene-ethylene block copolymer and the like, and the density at 23 ° C. is 0.88. ~ 0.
Examples thereof include polypropylene having a melt flow rate of 0.1 to 100 dg / min at 93 g / cm ³ and 230 ° C., and (5) polybutene.

These polyethylene, polypropylene,
Polyolefins such as polybutene are problematic if they are crystalline
It can be used without any use, and its crystallinity is 20%.
The above polyolefins are preferable. These polies
Polyolefins such as ethylene, polypropylene and polybutene
These may be used alone or as a mixture. this
Of these, the Ziegler Natta type or metallocene type
Represented by a catalyst system that imparts stereoregularity to the polymer
Produced by propylene homopolymer, propylene-ethylene
Tylene random copolymer, propylene-ethylene block
Copolymers such as polypropylene, and their polypropylenes
A mixture of pyrene is more preferred. Functionalized polyolefin resin The functionalized polyolefin-based resin used in the present invention is, for example,
For example, it can be selected from the resins shown below.
Polyolefin-based molecular structure and water
Acid group, amino group, carboxylic acid group, carboxylic acid anhydride group
It is not a resin that has at least one functional group in the same molecular chain.
It can be preferably used. (1) Graft-modified polyolefin The above-mentioned polyolefin resin having a molecular weight of 20,000 or less
Low molecular weight polyolefin resin, ethylene-
Propylene rubber, ethylene-propylene-diene rubber,
Butadiene rubber, styrene-butadiene rubber, hydrogenated steel
Len-butadiene rubber, styrene-isoprene rubber, water
Styrene-isoprene rubber and other olefinic elastomers
Base resin that is either one of the polymers or a mixture thereof
In contrast, maleic acid, itaconic acid, methacrylic acid, acetic acid
Unsaturated carboxylic acids such as phosphoric acid, maleic anhydride, anhydrous
Unsaturated carboxylic acid anhydrides such as itaconic acid, methacryl
2-hydroxyethyl acid, 2-hydroxyethyl acrylate
Chill, 2-hydroxypropyl methacrylate, acrylic
Acid 2-hydroxypropyl, methacrylic acid 3-hydroxy
Cypropyl, 3-hydroxypropyl acrylate, meta
Glyceryl acrylate, pentaerythritol methacrylate
, Polyethylene glycol methacrylate, methacrylic
Having a hydroxyl group at the end of polypropylene glycol, etc.
Unsaturated carboxylic acid esters, glycidyl methacrylate
Have an epoxy group at the end of glycidyl acrylate, etc.
Unsaturated carboxylic acid esters or allyl alcohol
Reactions containing functional groups such as unsaturated alcohols
A reactive monomer with an organic peroxide or electron beam
Perform a grafting reaction using the generated radicals
Graft-modified polyolefin obtained by the above, and
The functionalized ends of these graft-modified polyolefins are
In the same molecule such as amine, diol, amino alcohol
Remodification of functional groups using compounds with two or more functional groups
The remodified polyolefin obtained can be preferably used.

The amount of the reactive monomer bonded to the base resin of these graft modified polyolefin and remodified polyolefin is preferably 0.01 to 10% by weight,
0.05 to 5% by weight is particularly preferred. If it is 0.01% by weight or less, the coating adhesion is lowered, and if it is 10% by weight or more, mechanical properties, weather resistance, etc., which are the original characteristics of polyolefin, are lowered. (2) Ethylene-based multi-component copolymer: ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-maleic anhydride copolymer, ethylene-methacrylic acid hydroxyalkyl ester Copolymer, saponified product of ethylene-vinyl acetate copolymer, ethylene-α-olefin-methacrylic acid copolymer, ethylene-α-olefin-acrylic acid copolymer, ethylene-α-olefin-
Glycidyl methacrylate copolymer, ethylene-α-olefin-maleic anhydride copolymer, ethylene-α-olefin-methacrylic acid hydroxyalkyl ester copolymer, saponified ethylene-α-olefin-vinyl acetate copolymer, ethylene-methacryl Acid alkyl ester-methacrylic acid copolymer, ethylene-methacrylic acid alkyl ester-acrylic acid copolymer, ethylene-methacrylic acid alkyl ester-glycidyl methacrylate copolymer, ethylene-methacrylic acid alkyl ester-maleic anhydride copolymer , Ethylene-methacrylic acid alkyl ester-methacrylic acid hydroxyalkyl ester copolymer, ethylene-acrylic acid alkyl ester-methacrylic acid copolymer, ethylene-acrylic acid alkyl ester-acrylic acid copolymer Ethylene-based multi-component copolymers such as ethylene-acrylic acid alkyl ester-glycidyl methacrylate copolymer, ethylene-acrylic acid alkyl ester-maleic anhydride copolymer, ethylene-acrylic acid alkyl ester-methacrylic acid hydroxyalkyl ester copolymer Coalescence can be preferably used.

The weight ratio of the reactive monomer unit such as methacrylic acid contained in the molecule of these ethylene-based multi-component copolymers to the whole resin is preferably 0.01 to 40% by weight, and 0.05 to 20% by weight. % Is particularly preferred. 0.01
If it is less than 50% by weight, the coating adhesion will be reduced, and if it is more than 40% by weight, the mechanical properties which are the original characteristics of polyolefin,
Weather resistance and the like are reduced.

These graft-modified polyolefin, re-modified polyolefin and ethylene-based multi-component copolymer can be used alone or as a mixture of two or more kinds. Is it a functionalized polyolefin resin and a polyolefin resin?
Resin consisting of the functionalized polyolefin resin used in the present invention and the ratio of the functionalized polyolefin resin in the resin composed of the polyolefin resin is preferably 5% by weight or more, and further 1
0% by weight or more is particularly preferable. If it is less than 5% by weight, the coating adhesion will be insufficient.

The resin composed of the functionalized polyolefin resin and the polyolefin resin used in the present invention includes ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-propylene-butene rubber, bradiene rubber and the like. Polyolefin rubber, styrene-
Styrene-olefin rubber such as butadiene rubber, hydrogenated styrene-butadiene rubber, styrene-isoprene rubber, hydrogenated styrene-isoprene rubber, talc, calcium carbonate, glass fiber, potassium titanate, inorganic filler such as magnesium oxysulfate, polyester ,
Organic fillers such as polyamides, phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, hindered amine weathering agents, flame retardants, lubricants, additives such as colorants, etc., alone or in any combination. Even if the selected ones are mixed, they can be used without any problem. Injection molding method Generally, when performing injection molding of polyolefin resin,
Molding and cooling of the resin are performed by controlling the mold temperature to about 40 to 60 ° C. with a temperature controller. That is, the mold temperature is always kept extremely lower than the crystallization temperature of the resin. When molding a resin consisting of a functionalized polyolefin resin and a polyolefin resin using this method, the crystallinity of the molecular chain part where the functional group is not bonded is the crystallinity of the molecular chain part where the functional group is bonded. In the process of cooling and solidifying a flowing resin, the functional chain is not crystallized on the outermost surface that contacts the mold. The low-crystallinity molecular chain portion is trapped inside. That is, the molecular chain portion to which the functional group is bonded cannot be effectively arranged on the outermost surface, which greatly affects the adhesion of the coating.

Unlike the above-mentioned injection molding, hot press molding does not involve a high-speed resin flow and has a highly crystalline molecular chain portion to which a functional group is not bonded, and a crystalline chain portion to which a functional group is bonded. The low molecular chain portion is easily distributed evenly in the molded product, and the molecular chain portion where the functional group is bonded due to the affinity of the functional group with the surface of the mold is easily arranged on the outermost layer, so the coating is hardened during coating. At the time of reaction, an organic bond between the outermost surface of the molded product and the coating material is generated, and the coating adhesion is improved. However, although hot press molding can provide good coating adhesion, the molding cycle is long and not practical.

In order to produce a molded article having good coating adhesion and surface gloss with good productivity, it is necessary to preheat the surface of the die to be used and then perform injection molding.
It is preferable to use a method in which an injection molding machine equipped with a high-frequency heater described in JP-B-58-40504 is used to preheat the surface of the mold and then perform injection molding. The surface temperature of the mold is preferably preheated to 100 ° C. or higher, and the functionalized polyolefin resin DSC is used.
It is particularly preferable to set the crystallization peak temperature or the DSC crystallization peak temperature of the polyolefin-based resin, whichever is higher, whichever is higher.

The injection speed in injection molding can be set arbitrarily, and for example, low speed injection molding of about 10 mm / sec and high speed injection molding of about 1000 mm / sec can be used without any particular problem. As a similar method, it is also possible to use an injection press method in which an injected resin is put between molds and further press molding is performed.

In order to improve the surface gloss and sharpness after coating, it is preferable that the surface of the above-mentioned molded product has a 60 ° gloss gloss (ASTM-D523) of at least 60% or more. It is preferably 70% or more,
It is particularly preferably 80% or more. Concentration Ratio of Specific Element on Outermost Surface of Molded Article The element concentration ratio on the outermost surface of the molded article used in the present invention represents the density on the outermost surface of the functional group in the functionalized polyolefin that is involved in coating adhesion. That is, it is a functional group such as a hydroxyl group, an amino group, a carboxylic acid group, or a carboxylic acid anhydride group that is involved in the coating adhesion, from the functionalized polyolefin resin and the polyolefin resin in which these functional groups do not exist on the outermost surface. The injection-molded product of the resin does not show good coating adhesion.

The concentration of these functional groups on the outermost surface can be evaluated by the ratio of the concentrations of specific elements on the outermost surface, and the range is the oxygen concentration (C _O ) on the outermost surface of the molded product,
For carbon concentration (C _C ) and nitrogen concentration (C _N ), (C
_O + C _N ) / C _C is 0.005 to 0.300,
It is more preferably 0.010 to 0.200, and particularly preferably 0.015 to 0.150. If the concentration ratio of the specific element on the outermost surface of the molded product is smaller than the lower limit of the range described above, good coating adhesion cannot be obtained, and if it is larger than the range described above, it firmly adheres to the coating film. The outermost surface layer is peeled off from the molded article together with the coating film, so-called surface layer peeling occurs, and the weather resistance which is a characteristic of the polyolefin resin is deteriorated, which is not preferable.

The ratio of the concentration of these elements on the outermost surface of the molded product is measured by ESCA (also called XPS) or a spectroscopic analysis method such as total reflection method FT-IR using a low refractive index dispersive crystal such as Ge. be able to. Of these, E
SCA (XPS) is preferable, and measurement can be performed at an analysis depth of 100 Å or less. ESCA is a characteristic soft X-ray generated from aluminum, magnesium, etc. of a light source, which irradiates a measurement sample placed under a high vacuum, and counts photoelectrons generated when each element contained in the measurement sample is excited. By measuring the photoelectron quantity according to the binding energy with a rate meter and a multi-channel analyzer,
The element is identified and the element concentration is quantified.
In addition, the photoelectrons generated by exciting each element are
The escape depth from the sample surface is very shallow, and therefore only elemental concentration information on the outermost surface of the sample can be obtained. Paint, and coating method The paint for coating the molded article obtained in the present invention is not particularly limited as long as it is a commonly used paint, alkyd paint, aminoalkyd paint, epoxy paint, polyurethane paint, A thermosetting acrylic paint or the like can be used.

The method of applying the paint to the molded product is not particularly limited as long as it is a commonly used coating method, and a coating method using a brush or a coating method using a spray gun can be used.

[0025]

EXAMPLES The present invention will be described in more detail with reference to the following examples, which are illustrative only and are not intended to limit the present invention. The raw materials used in Examples and Comparative Examples are as shown below. (1) Propylene homopolymer (hereinafter referred to as “PP1”) A propylene homopolymer having a density of 0.90 g / cm ³ and an MFI of 4.0 g / 10 min was used. (2) Propylene-ethylene block copolymer (hereinafter referred to as “PP2”) Density 0.90 g / cm ³ , MFI 4.0 g / 10 minutes,
A propylene-ethylene block copolymer having an ethylene content of 7.0% was used. (3) Modified polypropylene Powdery propylene homopolymer (density: 0.90 g
/ Cm ³ , MFI: 0.5 g / 10 min) 100 parts by weight, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane 0.24 parts by weight, and glycerin monomethacrylate. 1.5 parts by weight and tetrakis [methylene-3 (3 ', 5'-di-t-butyl-
4′-hydroxy) phenylpropionate] methane (MARK-AO60: manufactured by Asahi Denka Co., Ltd.) was mixed for 0.1 minutes with a Henschel mixer for 5 minutes, and a co-rotating twin-screw extruder with a vacuum vent (PCM45: (Made by Ikegai Iron Works)
Was subjected to reactive extrusion at glycerin monomethacrylate modified polypropylene (hereinafter referred to as "modified PP1")
Got 2.16k of this modified PP1 at 230 ° C
The melt flow rate under g load was 4 dg / min. (4) Modified polypropylene in which functional groups are remodified Powdery propylene homopolymer (density: 0.90 g
/ Cm ³ , MFI: 0.5 g / 10 minutes), 100 parts by weight, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane 0.20 parts by weight, and maleic anhydride. 1.5 parts by weight and tetrakis [methylene-3 (3 ', 5'-di-t-butyl-4'-hydroxy) phenylpropionate] methane (MARK-AO) which is a heat stabilizer.
60: Asahi Denka Co., Ltd.) was mixed with 0.1 part by weight of the mixture for 5 minutes with a Henschel mixer, and reactive extrusion was carried out in a co-rotating twin-screw extruder with a vacuum vent (PCM45: manufactured by Ikegai Tekko Co., Ltd.) to obtain maleic anhydride. A modified polypropylene was obtained.
Further, 100 parts by weight of this mixture and 5 parts by weight of hexamethylenediamine are mixed and kneaded by the above-mentioned co-rotating twin-screw extruder to prepare an amino group-modified PP (hereinafter referred to as "modified PP2").
(Indicated by) is obtained. The melt flow rate of the modified PP2 at 230 ° C. under a load of 2.16 kg was 70 dg / min.

[0026]

Example 1 Using modified PP1, Japanese Patent Publication No. 58-405
In an injection molding machine (SG100: manufactured by Sumitomo Heavy Industries) equipped with a high-frequency heater similar to the method described in 04, 10 cm × 10 c
Molding was carried out by attaching a mold capable of molding a flat plate of m × 2 mm in thickness. The oscillation frequency of the high-frequency heater is 6 kHz, the power is 30 kW, the heating time is 10 seconds, the injection pressure of the injection molding machine is 25 K / G, the injection time is 5 seconds, and the cooling time is 2 seconds.
By setting it to 5 seconds, a burr-free molded product was obtained. The mold surface temperature was 205 ° C. immediately after high-frequency heating. (1) Primary coating adhesion test The obtained flat plate was left for 2 days after molding, and a urethane gun was applied with a spray gun (Retan PG60: manufactured by Kansai Paint).
Is applied to a thickness of about 20 μm and left for 1 week, then JI
According to S-K5400, when a cross-cut was made at 1 mm intervals using a cutter knife on the coating film near the center of the molded product, and a cross-cut peeling test was performed using cellophane tape.
The number of cross-cuts remaining in 100 cross-cuts was 100, and no peeling of the coating was observed. (Hereinafter referred to as 100/100.) (2) Secondary adhesion test for coating The obtained flat plate was left for 2 days after molding, and then urethane paint was applied by a spray gun (Retan PG60: manufactured by Kansai Paint Co., Ltd.).
Is applied in a thickness of about 20 μm and left for 1 week, then 40
It was immersed in warm water of ° C and left for 240 hours. Then JI
According to S-K5400, when a cross-cut was made at 1 mm intervals using a cutter knife on the coating film near the center of the molded product, and a cross-cut peeling test was performed using cellophane tape.
It was 100/100, and peeling of the coating was not observed. (3) 60 ° gloss gloss measurement The obtained flat plate was left for 2 days after molding,
The gloss gloss was measured. Device is GLOS S M
ETER MODEL GM-26D (MURAKAM
I COLOR RESEARCH LABORATO
(Made by RY), using AS
When measured by a method according to TM-D523,
The 60 ° gloss gloss was 93%. (4) Element concentration ratio measurement of the outermost surface of the molded product For elemental analysis of the outermost surface of the molded product, cut out the vicinity of the center of the unpainted plate into a size of 8 mm × 8 mm, and use ESCA to measure the carbon, oxygen, and nitrogen of the outermost surface. When I measured the peak,
The oxygen / carbon concentration ratio (hereinafter referred to as “C _O / C _C ”) was 0.
023, which is the nitrogen / carbon concentration ratio (hereinafter "C _N / C _C ".
Was 0, and the (oxygen + nitrogen) / carbon concentration ratio (hereinafter referred to as “(C _O + C _N ) / C _C ”) was 0.023.

Details of the ESCA measuring method are as follows. (4-A) Device: ESCALAB200X (manufactured by VG) (4-B) X-ray source: magnesium (Kα) (4-C) source current, power: 20 mA, 14 kV (4-D) Sensor: channeltron ( 4-D) Degree of vacuum: 10 ^-8 mbar (4-E) Quantitative method for concentration ratio of outermost surface element C _O / C _C is the integral value of oxygen 1S peak appearing at binding energy of 532 eV, and relative sensitivity of oxygen (2 .85) was calculated by dividing the integrated value of the carbon 1S peak where the binding energy appears at 284 eV by the value corrected by the relative sensitivity of carbon (1.00).

C _N / C _C has a binding energy of 399e
The binding energy is 28 when the integrated value of the nitrogen 1S peak appearing in V is corrected by the relative sensitivity of nitrogen (1.77).
It was determined by dividing the integrated value of the carbon 1S peak appearing at 4 eV by the value corrected by the relative sensitivity (1.00) of carbon.
(C _O + C _N ) / C _C has a binding energy of 532 eV
The relative value of oxygen (1.
85) and the binding energy is 399 eV
The integrated value of the nitrogen 1S peak appearing in is the relative sensitivity of nitrogen (1.
77), the binding energy is 28
It was determined by dividing the integrated value of the carbon 1S peak appearing at 4 eV by the value corrected by the relative sensitivity (1.00) of carbon.

[0029]

[Example 2] Evaluation was performed under the same conditions as in Example 1 except that the heating time of the high-frequency heater was set to 7 seconds and the mold surface temperature immediately after high-frequency heating was 165 ° C. It was 100/100 and there was no peeling of the coating, and the secondary coating adhesion test was 99/100, and only slight peeling of the coating was observed. The outermost surface C _O / C _C ,
C _N / C _C and (C _O + C _N ) / C _C are each 0.01
The values were 3, 0 and 0.013.

[0030]

[Embodiment 3] The heating time of the high-frequency heater is set to 5 seconds, and high frequency
Performed except that the mold surface temperature immediately after wave heating was 135 ° C
When evaluated under the same conditions as in Example 1, the primary adhesion of coating
The test is 98/100, and the secondary coating adhesion test is 88
Only a slight peeling of the paint was seen as / 100.
It was The outermost surface C_O/ C_C, C_N/ C_C, (C_O+ C
_N) / C_CAre 0.007, 0 and 0.007 respectively.
It was

[0031]

[Comparative Example 1] The mold temperature was 50 ° C. without high frequency heating.
Evaluation was performed under the same conditions as in Example 1 except that the cooling time was 20 seconds.
When the value was evaluated, the paint primary adhesion test, the paint secondary adhesion
Both the sex tests were 0/100, and all the cross-cuts were peeled off.
The outermost surface CO / C_C, C _N/ C_C, (C_O+ C_N)
/ C_CWere 0.003, 0, and 0.003, respectively.

[0032]

Comparative Example 2 Except that PP1 was used instead of modified PP1
When evaluated under the same conditions as in Example 1, the primary
Both the adhesion test and the secondary coating adhesion test are 0/100,
All the grids were peeled off. The outermost surface C_O/ C_C, C_N
/ C_C, (C_O+ C_N) / C _CAre 0, 0, 0 respectively
It was.

[0033]

Comparative Example 3 Except that PP2 was used instead of modified PP1
When evaluated under the same conditions as in Example 1, the primary
Both the adhesion test and the secondary coating adhesion test are 0/100,
All the grids were peeled off. The outermost surface C_O/ C_C, C_N
/ C_C, (C_O+ C_N) / C _CAre 0, 0, 0 respectively
It was.

[0034]

[Example 4] The modified PP2 was used in place of the modified PP1, and the evaluation was carried out under the same conditions as in Example 1 except that the injection molding pressure was set to 15K / G. Both tests were 100/100, and no peeling of the cross-cut was observed. In addition, C _O / C _C and C _{N on the} outermost surface
/ C _C , (C _O + C _N ) / C _C are 0.024,
It was 0.019 and 0.043.

[0035]

[Comparative Example 4] The mold temperature was 50 ° C without high frequency heating.
Evaluation was performed under the same conditions as in Example 4 except that the cooling time was 20 seconds.
When the value was evaluated, the paint primary adhesion test, the paint secondary adhesion
Both the sex tests were 0/100, and all the cross-cuts were peeled off.
The outermost surface CO / C_C, C _N/ C_C, (C_O+ C_N)
/ C_CAre 0.002, 0.002 and 0.004 respectively
there were.

[0036]

Example 5 The same conditions as in Example 1 except that 40 parts by weight of PP2 and 60 parts by weight of modified PP1 were melt-kneaded in advance using a co-rotating twin-screw extruder instead of the modified PP1. As a result of the evaluation, it was 100/100 in both the primary coating adhesion test and the secondary coating adhesion test, and no cross-cut peeling was observed. The outermost surface C _O /
C _C , C _N / C _C , and (C _O + C _N ) / C _C are each 0.
It was 015, 0, and 0.015.

[0037]

[Comparative Example 5] The mold temperature was 50 ° C without high frequency heating.
Evaluation was performed under the same conditions as in Example 5 except that the cooling time was 20 seconds.
When the value was evaluated, the paint primary adhesion test, the paint secondary adhesion
Both the sex tests were 0/100, and all the cross-cuts were peeled off.
The outermost surface CO / C_C, C _N/ C_C, (C_O+ C_N)
/ C_CWere 0.002, 0 and 0.002, respectively.

[0038]

Example 6 Instead of modified PP1, modified PP was previously prepared.
Evaluation was carried out under the same conditions as in Example 1 except that 60 parts by weight of No. 1 and 40 parts by weight of calcium carbonate were melt-kneaded using a co-rotating twin-screw extruder. The secondary adhesion test for coating was 100/100, and no cross-cut peeling was observed. The outermost surface C _O / C _C , C _N / C _C , (C _O + C _N ) / C _C are
0.017, 0, 0.017 respectively, 60 after painting
The gloss gloss was also good at 98%.

[0039]

Comparative Example 6 The mold temperature was 50 ° C. without high frequency heating.
Evaluation was performed under the same conditions as in Example 6 except that the cooling time was 20 seconds.
When the value was evaluated, the paint primary adhesion test, the paint secondary adhesion
Both the sex tests were 0/100, and all the cross-cuts were peeled off.
The outermost surface CO / C_C, C _N/ C_C, (C_O+ C_N)
/ C_CAre 0.002, 0, 0.002, respectively,
The 60 ° gloss gloss after wearing is 89%, which is not good.
It was

[0040]

[Comparative Example 7] Modified PP1 was heat-pressed for 5 minutes at a temperature of 200 ° C and a pressure of 200K / G using an iron plate having a mirror-finished surface, and then cold-pressed at a temperature of 20 ° C and a pressure of 100K / G for 3 minutes. A pressed flat plate having a size of 10 cm × 10 cm × thickness of 2 mm was prepared. When evaluated by the method described in Example 1, both the primary coating adhesion test and the secondary coating adhesion test were 100/100, and no peeling of the cross-cut was observed, but the molding cycle was 10 minutes. Met. The outermost surface C _O / C _C , C _N / C _C , (C _O C _N ) / C _C are
0.033, 0, 0.033 respectively, 60 after painting
The gloss gloss was 91%.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

EFFECTS OF THE INVENTION According to the present invention, it is possible to obtain a polyolefin resin injection-molded article which is excellent in coating adhesion, surface smoothness, and image clarity after coating, and is subjected to coating pretreatment such as trichloroethane cleaning and primer treatment. Can be omitted.

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Claims (2)

[Claims] 1. Hydroxyl group, amino group, carboxylic acid group, anhydrous
Fewer functional groups selected from carboxylic acid groups and epoxy groups
Functionalized polyolefin resin 5 with at least one type bonded
~ 100 wt% and polyolefin resin 95-0 wt%
(1) Outermost table of resin injection molded products consisting of
Surface oxygen concentration (C_O), Carbon concentration (C _C), And nitrogen concentration
Degree (C_N) To (C_O+ C_N) / C_CBut 0.00
5 to 0.300, (2) 60 ° gloss gloss on the surface
Degree (ASTM-D523) is at least 60% or more
A polyolefin resin injection molded product characterized by the following. 2. A functionalized polyolefin resin 5 to which at least one functional group selected from a hydroxyl group, an amino group, a carboxylic acid group, a carboxylic acid anhydride group and an epoxy group is bonded.
~ 100 wt% and polyolefin resin 95-0 wt%
A method for molding a polyolefin-based resin injection-molded article, comprising the steps of: before injection-molding a resin made of, the mold surface on which the injection-molded article is to be formed is heated in advance and then injection-molded.