Modified polyolefin resin

Abstract

The present invention provides a modified polyolefin resin that can form a coating that exhibits excellent adhesion to a low-polarity base material, especially a poorly adherable polyolefin base material with no surface treatment even when being dried at low temperatures and has flexibility (bendability). Provided is a modified polyolefin resin that is a modified product of a polyolefin resin having a melting point (Tm) by a differential scanning calorimeter (DSC) of 60 to 165 C. with a modifier comprising the following (A): (A) a monomer mixture comprising Monomer Group (A-1) and Monomer Group (A-2) with a weight ratio of Monomer Group (A-1) to Monomer Group (A-2) ((A-1)/(A-2)) of 30/70 to 50/50.

Claims

1. A modified polyolefin resin, obtained by a process comprising: modifying a polyolefin resin having a melting point (Tm) measured by a differential scanning calorimeter (DSC) of 60 to 165 C. with a modifier, wherein the modifier comprises: (A) a monomer mixture comprising Monomer Group (A-1) and Monomer Group (A-2) with a weight ratio of Monomer Group (A-1) to Monomer Group (A-2) ((A-1)/(A-2)) of 30/70 to 50/50, and (B) chlorine: Monomer Group (A-1): two or more monomers comprising an ethylenically unsaturated bond and a functional group wherein when a homopolymer is made from each monomer of said two or more monomers said homopolymer has a glass transition temperature (Tg) of 60 C. or more, and Monomer Group (A-2): two or more monomers comprising an ethylenically unsaturated bond and a functional group wherein when a homopolymer is made from each monomer of said two or more monomers said homopolymer has a glass transition temperature (Tg) of 30 C. or less.

2. The modified polyolefin resin according to claim 1, wherein the functional group of the Monomer Group (A-1), the functional group of the Monomer Group (A-2), or both, is one or more selected from the group consisting of a carboxy group, a group represented by (CO)O, a hydroxy group, an ether group, and an optionally substituted amino group.

3. The modified polyolefin resin according to claim 1, wherein at least one of the one or more monomers included in Monomer Group (A-1) comprises a carboxyl group as the functional group.

4. The modified polyolefin resin according to claim 1, wherein Monomer Group (A-1) includes one or more selected from the group consisting of a (meth)acrylic acid and an alkyl (meth)acrylate.

5. The modified polyolefin resin according to claim 1, wherein at least one of the one or more monomers included in Monomer Group (A-2) comprises one or more selected from the group consisting of a hydroxy group and an ether group as the functional group.

6. The modified polyolefin resin according to claim 1, wherein Monomer Group (A-2) includes one or more selected from the group consisting of an alkyl (meth)acrylate, a hydroxyalkyl (meth)acrylate, and an alkoxy alkyl (meth)acrylate.

7. The modified polyolefin resin according to claim 1, wherein the modifier further comprises: (C) one or more selected from the group consisting of an ,-unsaturated carboxylic acid and a derivative thereof.

8. A resin composition, comprising the modified polyolefin resin according to claim 1.

9. An organic solvent-containing resin composition, comprising: the modified polyolefin resin according to claim 1; and an organic solvent.

10. An aqueous resin composition, comprising: the modified polyolefin resin according to claim 1; and water.

11. A method for manufacturing a modified polyolefin resin, the method comprising: modifying a polyolefin resin having a melting point (Tm) measured by a differential scanning calorimeter (DSC) of 60 to 165 C. with a modifier comprising: (A) a monomer mixture comprising Monomer Group (A-1) and Monomer Group (A-2) with a weight ratio of Monomer Group (A-1) to Monomer Group (A-2) ((A-1)/(A-2)) of 30/70 to 50/50, and (B) chlorine: Monomer Group (A-1): two or more monomers comprising an ethylenically unsaturated bond and a functional group wherein when a homopolymer is made from each monomer of said two or more monomers said homopolymer has a glass transition temperature (Tg) of 60 C. or more, and Monomer Group (A-2): two or more monomers comprising an ethylenically unsaturated bond and a functional group wherein when a homopolymer is made from each monomer of said two or more monomers said homopolymer has a glass transition temperature (Tg) of 30 C. or less.

12. The method according to claim 11, wherein the modifier further comprises: (C) one or more selected from the group consisting of an ,-unsaturated carboxylic acid and a derivative thereof.

13. The method according to claim 12, comprising modifying the polyolefin resin with the one or more selected from group consisting of (B) and (C) and then with (A).

Description

EXAMPLE

(1) The following describes the present invention in more detail with reference to examples and comparative examples; the present invention is not limited to these examples.

(2) A polyolefin resin and modified products thereof were manufactured in accordance with the following manufacture examples 1 to 5.

[Manufacture Example 1] Manufacture of Polyolefin Resin

(3) A propylene-based random copolymer (propylene unit content: 96% by weight, ethylene unit content: 4% by weight, melt flow rate (MFR)=2.0 g/min, and melting point (Tm)=125 C.) manufactured with a metallocene catalyst as a polymerization catalyst was supplied to a twin-screw extruder with a barrel temperature set at 350 C. and was subjected to thermal degradation to obtain a propylene-based random copolymer (a polyolefin resin) with a 190 C. melt viscosity of about 1,500 mPa.Math.s.

[Manufacture Example 2] Manufacture of Modified Product of Polyolefin Resin with Maleic Anhydride

(4) After sufficiently mixing in advance 100 parts by weight of the propylene-based random copolymer obtained in the manufacture example 1, 4 parts by weight of maleic anhydride, 2 parts by weight of lauryl methacrylate, and 3 parts by weight of dicumyl peroxide, the mixture was supplied to a twin-screw extruder (L/D=34, diameter=40 mm, and a first barrel to an eighth barrel) and were reacted with a dwell time of 5 minutes, a number of revolution of 300 rpm, and a barrel temperature of 120 C. (the first and the second barrels), 180 C. (the third and the fourth barrels), 100 C. (the fifth barrel), and 130 C. (the sixth to the eighth barrels), and unreacted maleic anhydride was removed by pressure reducing treatment in the sixth to eighth barrels to obtain a modified product of the polyolefin resin with maleic anhydride (MA).

[Manufacture Example 3] Manufacture of Modified Product of Polyolefin Resin with Chlorine

(5) Into a glass-lined reaction vessel, 500 g of the propylene-based random copolymer obtained in the manufacture example 1 was charged, 5 L of chloroform was added thereto, chlorine gas was blown from the bottom of the reaction vessel while being irradiated with ultraviolet rays under a pressure of 2 kg/cm.sup.2 to perform chlorination, and a resin-chloroform mixture was obtained. The chlorine content of the resin in the mixture was 20.5% by weight. Next, chloroform as a solvent was distilled off from the resin-chloroform mixture with an evaporator to prepare a chloroform solution with a solid content of 30% by weight. Epicoat 828 (manufactured by Yuka Shell Epoxy K. K.) as a stabilizer was added to this chloroform solution in an amount of 4% by weight relative to the solid content, and the mixture was supplied to a twin-screw extruder (L/D=34, diameter=40 mm, and a first barrel to a seventh barrel) and was solidified with a dwell time of 10 minutes, a number of revolution of 50 rpm, and a barrel temperature of 90 C. (the first to the sixth barrels) and 70 C. (the seventh barrel). Pressure reducing treatment was performed in the first and the fourth to the sixth barrels to obtain a modified product of the polyolefin resin with chlorine (Cl).

[Manufacture Example 4] Manufacture of Modified Product of Polyolefin Resin with Maleic Anhydride and Chlorine

(6) After sufficiently mixing in advance 100 parts by weight of the propylene-based random copolymer obtained in the manufacture example 1, 4 parts by weight of maleic anhydride, and 3 parts by weight of dicumyl peroxide, the mixture was supplied to a twin-screw extruder (L/D=34, diameter=40 mm, and a first barrel to an eighth barrel) and were reacted with a dwell time of 5 minutes, a number of revolution of 300 rpm, and a barrel temperature of 120 C. (the first and the second barrels), 180 C. (the third and the fourth barrels), 100 C. (the fifth barrel), and 130 C. (the sixth to the eighth barrels), and unreacted maleic anhydride was removed by pressure reducing treatment in the sixth to eighth barrels to obtain a propylene-based random copolymer modified with maleic anhydride. Into a glass-lined reaction vessel with a volume of 50 L, 2 kg of this copolymer was charged, 20 L of chloroform was added thereto, chlorine gas was blown from the bottom of the reaction vessel while being irradiated with ultraviolet rays under a pressure of 2 kg/cm.sup.2 to perform chlorination, and a resin-chloroform mixture was obtained. The chlorine content of the resin in the mixture was 21.6% by weight. Next, chloroform as a solvent was distilled off from the resin-chloroform mixture with an evaporator to prepare a chloroform solution with a solid content of 30% by weight. A stabilizer (t-butylphenyl glycidyl ether) was added to this chloroform solution in an amount of 1.5% by weight relative to the solid content, and the mixture was supplied to a twin-screw extruder (L/D=34, diameter=40 mm, and a first barrel to a seventh barrel) and was solidified with a dwell time of 10 minutes, a number of revolution of 50 rpm, and a barrel temperature of 90 C. (the first to the sixth barrels) and 70 C. (the seventh barrel). Pressure reducing treatment was performed in the first and the fourth to the sixth barrels to obtain a solid modified product of the polyolefin resin with maleic anhydride and chlorine.

[Manufacture Example 5] Manufacture of Polyolefin Resin

(7) Isotactic polypropylene (IPP) (melting point (Tm)=150 C.) manufactured with a Ziegler Natta catalyst as a polymerization catalyst was supplied to a twin-screw extruder with a barrel temperature set at 350 C. and was subjected to thermal degradation to obtain IPP (a polyolefin resin) with a 190 C. melt viscosity of about 2,000 mPa.Math.s. Next, in the exactly same manner as the manufacture example 4 except that the obtained IPP was used in place of the propylene-based random copolymer (the polyolefin resin) obtained in the manufacture example 1, obtained was a solid modified product of the polyolefin resin with maleic anhydride and chlorine with a chlorine content of 24.0% by weight.

(8) Table 2 lists the chlorine content, the graft amount of maleic anhydride, the weight average molecular weight, the number average molecular weight, and the degree of dispersion of the polyolefin resin and the modified products obtained in the manufacture examples 1 to 5.

(9) TABLE-US-00002 TABLE 2 Polyolefin resin or modified products of Manufacture Examples 1 to 5 Manu- Manu- Manu- Manu- Manu- facture facture facture facture facture Example 1 Example 2 Example 3 Example 4 Example 5 Chlorine 20.5% by 21.6% by 24.0% by content weight weight weight (relative to solid content) Graft 3.8% by 3.8% by 3.6% by amount of weight weight weight maleic anhydride (relative to solid content) Weight 51,000 55,000 65,000 60,000 60,000 average molecular weight (Mw) Number 26,800 29,000 33,000 30,700 27,300 average molecular weight (Mn) Degree of 1.90 1.90 1.97 1.95 2.20 dispersion (Mw/Mn)

Example 1

(10) Into a flask equipped with a stirrer, a thermometer, and a cooling pipe for refluxing monomers, 25 g of the propylene-based random copolymer obtained in the manufacture example 1 as a polyolefin resin and 100 g of toluene were charged, and the mixture was heated up to a temperature of 85 C. Next, 5 g of benzoyl peroxide was charged thereinto, and the mixture was stirred for 30 minutes, then 100 g of Mixture A as a monomer mixture having the composition ratio listed in Table 3-1 (3 g of methacrylic acid, 20 g of methyl methacrylate, 17 g of cyclohexyl methacrylate, 3 g of 2-hydroxyethyl acrylate, 24 g of 2-methoxyethyl acrylate, and 33 g of butyl methacrylate) was added thereto for about 3 hours, and further a graft copolymerization reaction was carried out for 7 hours to obtain a modified polyolefin resin as a uniform, transparent toluene solution (non-volatile content: 40% by weight). Next, a flexibility test and an adhesion test were carried out on the obtained modified polyolefin resin by the methods shown below. Table 4-1 lists the results.

(11) <Preparation of Coating Test Piece>

(12) After kneading 100 g of the modified polyolefin resin solution (solid content: 40% by weight) obtained in the example 1 and 20 g of titanium dioxide with a sand mill for 3 hours, xylene was added so as to give 13 to 15 sec/20 C. with a No. 4 Ford cup to adjust the viscosity of the obtained kneaded object. For a base material, an ultra-high-rigidity polypropylene (PP) plate (TX-933A manufactured by Mitsubishi Chemical Corporation) was used. The kneaded object subjected to viscosity adjustment was applied to the base material with an air spray gun and was dried at 80 C. for 30 minutes to obtain Coating Test Piece 1 with a film thickness of a modified polyolefin resin layer of 10 m. Next, two-part curing urethane paint (product name: Retan PG80 531 manufactured by Kansai Paint Co., Ltd.) was applied to Coating Test Piece 1 with an air spray gun, was dried at 80 C. for 30 minutes, and was left at room temperature for 24 hours, whereby a urethane resin layer (an overcoated layer) (film thickness: 30 m) was formed on the modified polyolefin resin layer (a pretreatment layer or a primer layer) to prepare Coating Test Piece 2.

(13) <Flexibility (Flex Resistance) Test>

(14) In conformity with JIS K5600-5-1, Coating Test Piece 1 was set in a bending testing apparatus having a cylindrical mandrel, and the flexibility of the coating at room temperature was visually evaluated.

(15) The following shows criteria:

(16) G: Good, there is no cracking in the coating.

(17) NG: Not good, there is cracking in the coating.

(18) <Adhesion Test>

(19) Notches reaching the base material were formed at intervals of 1 mm in the coating of Coating Test Piece 2 obtained above to divide the coating into 100 square sections. A piece of cellophane adhesive tape was brought into intimate contact therewith and was peeled off from the intimate contact surface in a 180 direction, and the degree of remaining of the coating was determined. The peeling of the coating includes the peeling of the coating from the base material (peeling at the interface between the base material and the modified polyolefin resin layer) and the peeling of the coating from the modified polyolefin resin layer (peeling at the interface between the modified polyolefin resin layer and the urethane resin layer); on which interface the peeling has occurred can be visually determined by difference in reflected light or the like. The following shows criteria:

(20) B: Best, no peeling is observed in the coating.

(21) G: Good, there is practically no problem, although peeling is observed in some degree at edges of some sections of the coating.

(22) NG1: Slightly bad, peeling is observed at the interface between the primer layer (the modified polyolefin resin layer) and the overcoated layer (the urethane resin layer).

(23) NG2: Bad, peeling from the base material is observed.

Examples 2 to 30 and Comparative Examples 1 to 15

(24) Operations similar to those of the example 1 were performed using polyolefin resins or modified products listed in Table 4-1 and Table 4-2 as polyolefin resins or modified products and using monomer mixtures listed in Table 4-1 and Table 4-2 as monomer mixtures to obtain modified polyolefin resins of examples 2 to 30 and comparative examples 1 to 15 as toluene solutions (non-volatile content: 40% by weight). For each of the obtained modified polyolefin resins, a flexibility test and an adhesion test were carried out in a manner similar to the example 1. Table 4-1 and Table 4-2 list the results. In Table 4-1 and Table 4-2, Cl means that they are modified with chlorine, whereas MA means that they are modified with maleic anhydride.

(25) Table 3-1, Table 3-2, and Table 3-3 list the compositions of Mixtures A to I used in examples 1 to 30 and comparative examples 1 to 15. In Table 3-1 to Table 3-3, the unit of Homopolymer Tg and Total Tg is Celsius degree. The composition ratio of the monomers contained in each of the mixtures is a weight ratio.

(26) TABLE-US-00003 TABLE 3-1 Monomer compositions of Mixtures A to C Homo- polymer Monomer Functional group Tg Mixture A Mixture B Mixture C A-1 Acrylic acid AA Carboxy 103 group Methacrylic acid MAA Carboxy 228 3 3 3 group Methyl MMA Ester 105 20 15 15 methacrylate group Ethyl methacrylate EMA Ester 65 group Isopropyl IPMA Ester 81 methacrylate group t-Butyl t- Ester 107 methacrylate BMA group Cyclohexyl CHMA Ester 83 17 14 30 methacrylate group Isobornyl IBMA Ester 155 methacrylate group A-2 Hydroxyethyl HEA Ester Hydroxy 15 3 acrylate group group Hydroxypropyl HPA Ester Hydroxy 7 3 acrylate group group Hydroxybutyl HBA Ester Hydroxy 32 3 acrylate group group 2-methoxyethyl MEA Ester Ether 50 24 acrylate group group 2-methoxyethyl MEMA Ester Ether 2 35 methacrylate group group 3-methoxybutyl MBA Ester Ether 56 acrylate group group Tetrahydrofurfuryl THFA Ester Ether 12 20 acrylate group group Butyl methacrylate BMA Ester 20 33 30 29 group Lauryl LMA Ester 65 methacrylate group n-Butyl acrylate BA Ester 54 group (A-1)/(A-2) 40/60 32/68 48/52 Total Tg 22.4 15.3 29.8

(27) TABLE-US-00004 TABLE 3-2 Monomer compositions of Mixtures D to F Homo- polymer Monomer Functional group Tg Mixture D Mixture E Mixture F A-1 Acrylic acid AA Carboxy 103 group Methacrylic acid MAA Carboxy 228 3 3 3 group Methyl MMA Ester 105 methacrylate group Ethyl methacrylate EMA Ester 65 group Isopropyl IPMA Ester 81 methacrylate group t-Butyl t- Ester 107 20 15 30 methacrylate BMA group Cyclohexyl CHMA Ester 83 17 14 15 methacrylate group Isobornyl IBMA Ester 155 methacrylate group A-2 Hydroxyethyl HEA Ester Hydroxy 15 3 acrylate group group Hydroxypropyl HPA Ester Hydroxy 7 3 acrylate group group Hydroxybutyl HBA Ester Hydroxy 32 3 acrylate group group 2-methoxyethyl MEA Ester Ether 50 acrylate group group 2-methoxyethyl MEMA Ester Ether 2 29 methacrylate group group 3-methoxybutyl MBA Ester Ether 56 24 acrylate group group Tetrahydrofurfuryl THFA Ester Ether 12 30 acrylate group group Butyl methacrylate BMA Ester 20 group Lauryl LMA Ester 65 33 35 20 methacrylate group n-Butyl acrylate BA Ester 54 group (A-1)/(A-2) 40/60 32/68 48/52 Total Tg 14.8 9.3 18.8

(28) TABLE-US-00005 TABLE 3-3 Monomer compositions of Mixtures G to I Homo- polymer Monomer Functional group Tg Mixture G Mixture H Mixture I A-1 Acrylic acid AA Carboxy 103 3 3 group Methacrylic acid MAA Carboxy 228 group Methyl MMA Ester 105 7 methacrylate group Ethyl methacrylate EMA Ester 65 30 group Isopropyl IPMA Ester 81 27 methacrylate group t-Butyl t- Ester 107 methacrylate BMA group Cyclohexyl CHMA Ester 83 methacrylate group Isobornyl IBMA Ester 155 10 methacrylate group A-2 Hydroxyethyl HEA Ester Hydroxy 15 3 3 acrylate group group Hydroxypropyl HPA Ester Hydroxy 7 acrylate group group Hydroxybutyl HBA Ester Hydroxy 32 acrylate group group 2-methoxyethyl MEA Ester Ether 50 20 30 acrylate group group 2-methoxyethyl MEMA Ester Ether 2 methacrylate group group 3-methoxybutyl MBA Ester Ether 56 acrylate group group Tetrahydrofurfuryl THFA Ester Ether 12 acrylate group group Butyl methacrylate BMA Ester 20 17 17 100 group Lauryl LMA Ester 65 methacrylate group n-Butyl acrylate BA Ester 54 30 group (A-1)/(A-2) 60/40 20/80 0/100 Total Tg 27.9 17.3 20

(29) TABLE-US-00006 TABLE 4-1 Evaluation results of examples Polyolefin resin or modified product Modification raw material of Monomer modified product mixture (B) (C) (A-1/A-2) Flexibility Adhesion Ex. 1 Manufacture Ex. 1 Mixture A G G Ex. 2 Manufacture Ex. 1 Mixture B G G Ex. 3 Manufacture Ex. 1 Mixture C G G Ex. 4 Manufacture Ex. 1 Mixture D G G Ex. 5 Manufacture Ex. 1 Mixture E G G Ex. 6 Manufacture Ex. 1 Mixture F G G Ex. 7 Manufacture Ex. 2 MA Mixture A G G Ex. 8 Manufacture Ex. 2 MA Mixture B G G Ex. 9 Manufacture Ex. 2 MA Mixture C G G Ex. 10 Manufacture Ex. 2 MA Mixture D G G Ex. 11 Manufacture Ex. 2 MA Mixture E G G Ex. 12 Manufacture Ex. 2 MA Mixture F G G Ex. 13 Manufacture Ex. 3 Cl Mixture A G G Ex. 14 Manufacture Ex. 3 Cl Mixture B G G Ex. 15 Manufacture Ex. 3 Cl Mixture C G G Ex. 16 Manufacture Ex. 3 Cl Mixture D G G Ex. 17 Manufacture Ex. 3 Cl Mixture E G G Ex. 18 Manufacture Ex. 3 Cl Mixture F G G Ex. 19 Manufacture Ex. 4 Cl MA Mixture A G B Ex. 20 Manufacture Ex. 4 Cl MA Mixture B G G Ex. 21 Manufacture Ex. 4 Cl MA Mixture C G G Ex. 22 Manufacture Ex. 4 Cl MA Mixture D G G Ex. 23 Manufacture Ex. 4 Cl MA Mixture E G G Ex. 24 Manufacture Ex. 4 Cl MA Mixture F G G Ex. 25 Manufacture Ex. 5 Cl MA Mixture A G B Ex. 26 Manufacture Ex. 5 Cl MA Mixture B G G Ex. 27 Manufacture Ex. 5 Cl MA Mixture C G G Ex. 28 Manufacture Ex. 5 Cl MA Mixture D G G Ex. 29 Manufacture Ex. 5 Cl MA Mixture E G G Ex. 30 Manufacture Ex. 5 Cl MA Mixture F G G

(30) TABLE-US-00007 TABLE 4-2 Evaluation results of comparative examples Polyolefin resin or modified product Modification raw material of modified Monomer product mixture (B) (C) (A-1/A-2) Flexibility Adhesion Comparative Ex. 1 Manufacture Mixture G G NG2 Ex. 1 Comparative Ex. 2 Manufacture Mixture H G NG2 Ex. 1 Comparative Ex. 3 Manufacture Mixture I G NG2 Ex. 1 Comparative Ex. 4 Manufacture MA Mixture G G NG2 Ex. 2 Comparative Ex. 5 Manufacture MA Mixture H G NG2 Ex. 2 Comparative Ex. 6 Manufacture MA Mixture I G NG2 Ex. 2 Comparative Ex. 7 Manufacture Cl Mixture G G NG2 Ex. 3 Comparative Ex. 8 Manufacture Cl Mixture H G NG2 Ex. 3 Comparative Ex. 9 Manufacture Cl Mixture I G NG2 Ex. 3 Comparative Manufacture Cl MA Mixture G G NG2 Ex. 10 Ex. 4 Comparative Manufacture Cl MA Mixture H G NG2 Ex. 11 Ex. 4 Comparative Manufacture Cl MA Mixture I G NG2 Ex. 12 Ex. 4 Comparative Manufacture Cl MA Mixture G G NG2 Ex. 13 Ex. 5 Comparative Manufacture Cl MA Mixture H G NG2 Ex. 14 Ex. 5 Comparative Manufacture Cl MA Mixture I G NG2 Ex. 15 Ex. 5

(31) The following is clear from the results listed in Table 4-1 and Table 4-2.

(32) The modified polyolefin resins of examples 1 to 30 can form the coating that is excellent in flexibility and is excellent in adhesion to the base material and adhesion to the overcoated layer on the base material (polypropylene).

(33) In contrast, the modified polyolefin resins of comparative examples 1 to 15, in which Mixture I, in which Monomer (A-1) is not contained in the monomer mixture, is used and Mixture G or Mixture H, in which the weight ratio of Monomer (A-1) to Monomer (A-2) ((A-1)/(A-2)) is out of the range of 30/70 to 50/50, is used, are not bad in flexibility, but are poor in adhesion, and thus do not satisfy both flexibility and adhesion.

(34) It is revealed from the foregoing results that the modified polyolefin resin of the present invention can form a coating having flexibility (bendability) to, not only a polar base material, even a low-polarity base material (a nonpolar base material), especially a poorly adherable polyolefin-based base material with no surface treatment and has excellent adhesion even when being dried at low temperatures. It is also revealed that the modified polyolefin resin of the present invention is excellent as a pretreatment agent such as a primer.

(35) <Examples of Aqueous Resin Composition>

Example 31

(36) To a four-neck flask equipped with a stirrer, a cooling pipe, a thermometer, and a dropping funnel, 100 parts by weight of the propylene-based random copolymer obtained in the manufacture example 1 and 10 parts by weight of a polyoxyethylene alkyl ether as a surfactant were added and were kneaded at 120 C. for 30 minutes. Next, 10 parts by weight of 2-amino-2-methyl-1-propanol was added thereto for 5 minutes, and the mixture was maintained for 5 minutes, and 300 parts by weight of ion exchanged water at 90 C. was added thereto for 40 minutes. Subsequently, the mixture was cooled to room temperature while stirring it to obtain a modified polyolefin resin as an aqueous resin composition. The solid content of the aqueous resin composition containing the modified polyolefin resin was 30% by weight, the pH thereof was 9.0, and the average particle diameter thereof was 280 nm. Next, Coating Test Piece 1 and Coating Test Piece 2 were prepared in a manner similar to the operations described in the example 1 except that the aqueous resin composition containing the modified polyolefin resin was used in place of the modified polyolefin resin solution obtained in the example 1, and a flexibility test and an adhesion test were carried out thereon. Table 5-1 lists the results.

Examples 32 to 60 and Comparative Examples 16 to 30

(37) Operations similar to those of the example 31 were performed using polyolefin resins or modified products listed in Table 5-1 and Table 5-2 as polyolefin resins or modified products and using monomer mixtures listed in Table 5-1 and Table 5-2 as monomer mixtures to obtain modified polyolefin resins of examples 32 to 60 and comparative examples 16 to 30 as aqueous resin compositions (non-volatile content: 30% by weight). Coating Test Piece 1 and Coating Test Piece 2 were prepared in a manner similar to the operations of the example 31 using the aqueous resin compositions containing the respective modified polyolefin resins, and a flexibility test and an adhesion test were carried out thereon. Table 5-1 and Table 5-2 list the results. In Table 5-1 and Table 5-2, Cl represents that the resins are modified with chlorine, whereas MA represents that the resins are modified with maleic anhydride.

(38) TABLE-US-00008 TABLE 5-1 Evaluation results of examples Polyolefin resin or modified product Modification raw material of Monomer modified product mixture (B) (C) (A-1/A-2) Flexibility Adhesion Ex. 31 Manufacture Ex. 1 Mixture A G G Ex. 32 Manufacture Ex. 1 Mixture B G G Ex. 33 Manufacture Ex. 1 Mixture C G G Ex. 34 Manufacture Ex. 1 Mixture D G G Ex. 35 Manufacture Ex. 1 Mixture E G G Ex. 36 Manufacture Ex. 1 Mixture F G G Ex. 37 Manufacture Ex. 2 MA Mixture A G G Ex. 38 Manufacture Ex. 2 MA Mixture B G G Ex. 39 Manufacture Ex. 2 MA Mixture C G G Ex. 40 Manufacture Ex. 2 MA Mixture D G G Ex. 41 Manufacture Ex. 2 MA Mixture E G G Ex. 42 Manufacture Ex. 2 MA Mixture F G G Ex. 43 Manufacture Ex. 3 Cl Mixture A G G Ex. 44 Manufacture Ex. 3 Cl Mixture B G G Ex. 45 Manufacture Ex. 3 Cl Mixture C G G Ex. 46 Manufacture Ex. 3 Cl Mixture D G G Ex. 47 Manufacture Ex. 3 Cl Mixture E G G Ex. 48 Manufacture Ex. 3 Cl Mixture F G G Ex. 49 Manufacture Ex. 4 Cl MA Mixture A G B Ex. 50 Manufacture Ex. 4 Cl MA Mixture B G G Ex. 51 Manufacture Ex. 4 Cl MA Mixture C G G Ex. 52 Manufacture Ex. 4 Cl MA Mixture D G G Ex. 53 Manufacture Ex. 4 Cl MA Mixture E G G Ex. 54 Manufacture Ex. 4 Cl MA Mixture F G G Ex. 55 Manufacture Ex. 5 Cl MA Mixture A G B Ex. 56 Manufacture Ex. 5 Cl MA Mixture B G G Ex. 57 Manufacture Ex. 5 Cl MA Mixture C G G Ex. 58 Manufacture Ex. 5 Cl MA Mixture D G G Ex. 59 Manufacture Ex. 5 Cl MA Mixture E G G Ex. 60 Manufacture Ex. 5 Cl MA Mixture F G G

(39) TABLE-US-00009 TABLE 5-2 Evaluation results of comparative examples Polyolefin resin or modified product Modification raw material of modified Monomer product mixture Flexi- Ad- (B) (C) (A-1/A-2) bility hesion Comparative Manufacture Mixture G G NG2 Ex. 16 Ex. 1 Comparative Manufacture Mixture H G NG2 Ex. 17 Ex. 1 Comparative Manufacture Mixture I G NG2 Ex. 18 Ex. 1 Comparative Manufacture MA Mixture G G NG2 Ex. 19 Ex. 2 Comparative Manufacture MA Mixture H G NG2 Ex. 20 Ex. 2 Comparative Manufacture MA Mixture I G NG2 Ex. 21 Ex. 2 Comparative Manufacture Cl Mixture G G NG2 Ex. 22 Ex. 3 Comparative Manufacture Cl Mixture H G NG2 Ex. 23 Ex. 3 Comparative Manufacture Cl Mixture I G NG2 Ex. 24 Ex. 3 Comparative Manufacture Cl MA Mixture G G NG2 Ex. 25 Ex. 4 Comparative Manufacture Cl MA Mixture H G NG2 Ex. 26 Ex. 4 Comparative Manufacture Cl MA Mixture I G NG2 Ex. 27 Ex. 4 Comparative Manufacture Cl MA Mixture G G NG2 Ex. 28 Ex. 5 Comparative Manufacture Cl MA Mixture H G NG2 Ex. 29 Ex. 5 Comparative Manufacture Cl MA Mixture I G NG2 Ex. 30 Ex. 5

(40) From the results listed in Table 5-1 and Table 5-2, the modified polyolefin resins of the examples 31 to 60 can form the coating that is excellent in flexibility and is excellent in adhesion to the base material and adhesion to the overcoated layer on the base material (polypropylene). The modified polyolefin resins of Comparative examples 16 to 30, in which Mixture I, Mixture G, or Mixture H is used, are not bad in flexibility, but are poor in adhesion, and thus do not satisfy both flexibility and adhesion.

(41) It is revealed from the foregoing results that, even when being made into the aqueous resin composition, the modified polyolefin resin of the present invention can form a coating having flexibility (bendability) to, not only a polar base material, even a low-polarity base material (a nonpolar base material), especially a poorly adherable polyolefin-based base material with no surface treatment and has excellent adhesion even when being dried at low temperatures. It is also revealed that, even when being made into the aqueous resin composition, the modified polyolefin resin of the present invention is excellent as a pretreatment agent (e.g., a primer).