JP2000234004A - Thermoplastic resin and its molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide thermoplastic resins having good adhesion to metals or polar resins and blending properties while retaining mechanical properties as olefin polymers. SOLUTION: A thermoplastic resin of the multi-layer construction type is a graft copolymer composed of 30-99 wt.% olefin polymer segment having a number average molecular weight of 5,000-1,000,000 synthesized by a metallocene catalyst and 1-70 wt.% vinyl (co)polymer segment having a number average molecular weight of 400-1,000,000 formed from one or more vinyl monomers containing a polar vinyl monomer in which one of the segments has been dispersed in the other segment in the form of particles having a particle diameter of 0.001-10 μm. Molded products are obtained by subjecting the thermoplastic resin to fabrication.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an adhesive property of a metal or a polar resin, for example, a copolymer of an olefin with a polar vinyl monomer such as polyamide, polyester or ethylene / vinyl acetate copolymer. And a molded article thereof.

[0002]

2. Description of the Related Art Ethylene or propylene-based polymers have excellent mechanical properties and moldability, so that various molded products,
Widely used for film applications. However, when these polymers are used in a method such as lamination or blending with other resins, metal foils, or the like, there is a problem in adhesiveness, blending properties, and the like due to low affinity with these materials.

In order to solve these problems, for example, a polymer obtained by blending a polar polymer with an ethylene copolymer (Japanese Patent Laid-Open Publication No. 51-109943) or radical polymerization of an ethylene or propylene polymer with a polar monomer is started. A modified product grafted with dicumyl peroxide as an agent (Japanese Patent Application Laid-Open No. 9-3137) is disclosed.

[0004]

However, a blend of a polar polymer and a polymer having a low affinity for an ethylene polymer and a polar polymer has a low mechanical strength and a low film processability. Further, a product obtained by grafting a polar monomer with a radical polymerization initiator has an insufficient affinity with a polar material because the grafting ratio of the polar monomer is low. In addition, since unreacted monomers and the like easily remain, the moldability is poor.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to maintain good mechanical properties as an olefin-based polymer while maintaining good adhesion to a metal or a polar resin. An object of the present invention is to provide a thermoplastic resin having a property and a molded product thereof.

[0006]

In order to solve the above problems, a first aspect of the present invention is to provide an olefin polymer segment 30 having a number average molecular weight of 5,000 to 1,000,000 synthesized by a metallocene catalyst. ~ 99% by weight,
The number average molecular weight formed from one or more vinyl monomers including a polar vinyl monomer is 400 to 1,000,000
1 to 70% by weight of a vinyl (co) polymer segment
And a multiphase structure type thermoplastic resin in which one segment is dispersed in the other segment with a particle size of 0.001 to 10 μm.

A second invention is directed to an aqueous suspension of particles comprising an olefin polymer synthesized with a metallocene catalyst, wherein one or more vinyl monomers including a polar vinyl monomer, And a radical polymerization initiator, and heating the mixture under a condition where decomposition of the radical polymerization initiator does not substantially occur, and one or more vinyl monomers including the polar vinyl monomer After impregnating the peroxide-containing monomer and the radical polymerization initiator into the particles of the olefin polymer, the radical polymerization initiator decomposes the aqueous suspension, and the peroxide-bonding monomer The temperature is raised to a temperature at which peroxide bonds of the polymer do not substantially decompose, and one or more vinyl monomers including the polar vinyl monomer and a peroxide bond-containing monomer are reacted with an olefin polymer. Obtaining a grafted precursor to be copolymerized in the particles A first step and a second step of kneading the grafted precursor under melting at a temperature at which a peroxide bond derived from a peroxide bond-containing monomer is decomposed to obtain a graft copolymer. The obtained thermoplastic resin of the first invention.

[0008] A third invention is a molded article obtained by molding the thermoplastic resin of the first invention or the second invention. A fourth invention is the molded product according to the third invention, wherein the molded product is a laminate with a polar material.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic resin of the present invention is a copolymer having a specific structure and a specific physical property. That is, the copolymer is an olefin-based polymer segment (hereinafter abbreviated as A segment).
And a vinyl (co) polymer segment (hereinafter abbreviated as B segment) formed from one or more vinyl monomers including a polar vinyl monomer. And it is because the other segment has a particle size of 0.001 to 1 in the continuous phase formed by one segment.
This is a multiphase structure type thermoplastic resin finely dispersed at 0 μm. A simple mixture of an olefin-based polymer and a vinyl-based (co) polymer has a particle size exceeding 10 μm and does not form a uniform dispersed phase. Further, even in the case of a graft copolymer, if the number average molecular weight of the B segment is too small, it does not become a multiphase structure type.

The olefin polymer used in the present invention is a polymer synthesized from an olefin as a starting material using a metallocene catalyst. Here, the metallocene-based catalyst is a transition metal compound of Group IVB of the periodic table containing a ligand having a cyclopentadienyl skeleton, an organic aluminum oxy compound and a carrier, and an olefin formed from an organic aluminum compound if necessary. It is a catalyst for polymerization.

The olefin polymer synthesized with a metallocene catalyst is specifically, for example, an ethylene polymer or a propylene polymer, but the ethylene polymer is excellent in adhesiveness to a polar resin. Is preferred. The ethylene-based polymer has a constitutional unit derived from ethylene of 50 to 1
00% by weight, preferably 70 to 100% by weight, more preferably 80 to 100% by weight, and 0 to 3 structural units derived from an α-olefin having 3 to 20 carbon atoms.
-50% by weight, preferably 0-30% by weight, more preferably 0-20% by weight.

The α-olefin having 3 to 20 carbon atoms includes propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, -Dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like.

The polypropylene polymer synthesized with the metallocene catalyst used in the present invention means that the constituent unit derived from propylene is 50 to 100% by weight, preferably 70 to 100% by weight, more preferably 80 to 100% by weight. 100
0 to 50% by weight, preferably 0 to 30% by weight, more preferably 0 to 20% by weight, of a structural unit derived from an α-olefin having 3 to 20 carbon atoms.
It is. Here, the α-olefin having 3 to 20 carbon atoms is the same as the above-mentioned ethylene polymer.

Since the ethylene-based or propylene-based polymer is not polymerized with a conventional titanium-based catalyst but polymerized with a metallocene-based catalyst, it has a low melting point. There is a characteristic that is excellent.

The B segment must be a polymer formed from one or more vinyl monomers including a polar vinyl monomer, and is selected from polar vinyl monomers. It is formed from at least one kind of monomer or a mixed monomer of at least one kind of monomer selected from polar vinyl monomers and other monomers. The polar vinyl monomer is, for example, a (meth) acrylate ester having a polar functional group such as hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, or 3-hydroxypropyl (meth) acrylate; Α, β-unsaturated carboxylic acids such as acid, methacrylic acid, fumaric acid, maleic anhydride, itaconic acid, itaconic anhydride, bicyclo (2,2,1) -5-heptene 2,3-dicarboxylic acid, acrylic acid Unsaturated glycidyl group-containing monomers such as glycidyl, glycidyl methacrylate, and monoglycidyl itaconate; aminoethyl (meth) acrylate; propylaminoethyl (meth) acrylate; dimethylaminoethyl (meth) acrylate; ) Aminoalkyl (meth) acrylates such as aminopropyl acrylate Examples include stearyl derivatives, allylamine, methacrylamine, and allylamine derivatives such as N, N-dimethylacrylamide.

Among these, polar vinyl monomers having at least one functional group selected from a hydroxyl group, an epoxy group, an amino group and a carboxyl group, such as hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) Acrylate, glycidyl acrylate, glycidyl methacrylate, aminoethyl (meth) acrylate, propylaminoethyl (meth) acrylate, dimethylaminoethyl methacrylate, methacrylamine, N, N-dimethylacrylamide, acrylic acid, methacrylic acid, fumaric acid And maleic anhydride are preferred from the viewpoint of adhesiveness.

Specific examples of the other monomers include nuclear-substituted styrenes such as styrene, methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene and chlorostyrene, and α-methylstyrene and α-ethylstyrene. -Vinyl aromatic monomers such as substituted styrene, methyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, acrylic acid 2
(Meth) acrylate monomers such as ethylhexyl, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and isobutyl methacrylate; (meth)
(Meth) acrylic acid such as ethyl acrylate
20 alkyl esters, (meth) acrylonitrile,
Vinyl acetate, vinyl propionate, vinyl caproate,
Examples thereof include vinyl ester monomers such as vinyl caprylate, vinyl laurate, vinyl stearate, and vinyl vinyl acetate.

The number average molecular weight of the A segment of the present invention is:
Usually 5,000 to 1,000,000, preferably 10,
The range is from 000 to 500,000. If the number average degree of polymerization is less than 5,000 or more than 1,000,000, moldability tends to decrease.

The number average molecular weight of the B segment is usually 400 to 1,000,000, preferably 1000 to 5
It is in the range of 00,000. When the number average degree of polymerization is less than 400, the compatibility with the polar substance is deteriorated, and when the number average degree of polymerization exceeds 1,000,000, the melt viscosity tends to be high and the moldability tends to decrease.

The proportion of the A segment in the graft copolymer is usually 30 to 99% by weight, preferably 4% by weight.
0 to 95% by weight. The proportion of the B segment in the graft copolymer is usually 1 to 70% by weight, preferably 5 to 60% by weight.

If the proportion of the A segment in the graft copolymer is less than 30% by weight or the proportion of the B segment in the thermoplastic resin is 70% by weight or more, the moldability of a film or the like tends to decrease. is there. The proportion of the A segment in the graft copolymer is 99% by weight.
When the ratio is more than 1% or when the proportion of the B segment in the thermoplastic resin is less than 1% by weight, the compatibility with the polar substance tends to deteriorate.

Examples of the graft copolymer having a structure in which the olefin polymer segment and the vinyl copolymer segment are chemically bonded include, specifically, a graft copolymer, a block / graft copolymer, and a graft copolymer. Copolymers in which the polymer is bonded two-dimensionally or three-dimensionally can be exemplified. Above all, a graft copolymer is particularly preferred because of ease of production. Further, a homopolymer such as an olefin-based polymer or a vinyl-based (co) polymer may be contained in the thermoplastic resin without departing from the characteristics of the present invention. This is a product produced in the process of producing the copolymer or a product in which unreacted raw materials remain, but also includes a case where addition is adjusted for the purpose of improving physical properties. The proportion of the olefin polymer in the thermoplastic resin is usually 99% by weight or less, and the proportion of the vinyl (co) polymer in the thermoplastic resin is usually 70% by weight or less. If the amount of the olefin polymer exceeds 99% by weight, the adhesiveness to polar resins and the like tends to decrease, and if the amount of the vinyl (co) polymer exceeds 70% by weight, the moldability tends to decrease.

The method for producing the thermoplastic resin of the present invention comprises:
Any of the generally known chain transfer method, ionizing radiation irradiation method, and the like may be used, but the most preferable is grafting by melting and kneading the following grafting precursor (hereinafter abbreviated as precursor). This is a method for obtaining a copolymer. This is because the grafting efficiency is high and secondary aggregation due to heat does not occur, so that the expression of performance is more effective and the production method is simple.

Hereinafter, the method will be described in detail. First, 100 parts by weight of an olefin polymer synthesized with a metallocene catalyst is suspended in water. Then, 1 to 400 parts by weight of at least one vinyl monomer containing a polar vinyl monomer (hereinafter abbreviated as vinyl monomer) is added to the following formula (1)

[0025]

Embedded image

(Wherein R ¹ is a hydrogen atom or a group having 1 to 1 carbon atoms)
R ² is a hydrogen atom or a methyl group, R ³
And R ⁴ each represent an alkyl group having 1 to 4 carbon atoms, R ⁵
Represents an alkyl group having 1 to 12 carbon atoms, a phenyl group, an alkyl-substituted phenyl group, or a cycloalkyl group having 3 to 12 carbon atoms. m is 1 or 2. ) Or the following equation (2)

[0027]

Embedded image

(Wherein R ⁶ is a hydrogen atom or a C 1 -C 1)
4 alkyl groups, R ⁷ is a hydrogen atom or a methyl group, R ⁸ and R ⁹ are each an alkyl group having 1 to 4 carbon atoms, R ¹⁰ is an alkyl group having 1 to 12 carbon atoms, a phenyl group, an alkyl-substituted phenyl group or It represents a cycloalkyl group having 3 to 12 carbon atoms. n is 0, 1 or 2. )

One or two or more of the peroxide bond-containing monomers represented by the formula (1) are used in an amount of 0.1 to 20 parts by weight with respect to 100 parts by weight of the vinyl-based monomer, and are reduced by half in 10 hours. The radical polymerization initiator having a decomposition temperature of 40 to 90 ° C. for obtaining the period is 0.01 to 5 parts by weight based on 100 parts by weight of the total of the vinyl monomer and the peroxide bond-containing monomer. Is added. Next, the olefin (co) polymer is impregnated with the vinyl monomer, the peroxide bond-containing monomer and the radical polymerization initiator by heating under a condition that decomposition of the radical polymerization initiator does not substantially occur. When the impregnation rate reaches the initial 50% by weight or more, the temperature of the aqueous suspension is increased, and the vinyl monomer and the peroxide-containing monomer are copolymerized in the olefin polymer. The precursor is obtained by polymerization.

The graft copolymer of the present invention can be obtained by kneading the precursor in a molten state at a temperature at which a peroxide bond derived from a peroxide bond-containing monomer is decomposed. At this time, a thermoplastic resin can be obtained even if an olefin-based polymer or a vinyl-based (co) polymer is mixed into the precursor and melted and kneaded.

The melting and kneading temperature is 150 to 350.
° C. If the temperature is lower than 150 ° C., the melting is incomplete, or the melt viscosity is high and the mixing becomes insufficient, and phase separation or delamination appears in the molded product, which is not preferable. On the other hand, when the temperature exceeds 350 ° C., decomposition or gelation of the resin to be mixed easily occurs, which is not preferable.

As a method of melting and mixing, Banbury
It can be carried out by a commonly used kneading machine such as a mixer, a pressure kneader, a kneading extruder, a twin-screw extruder or a roll. In the present invention, within the scope not further deviating from the gist of the present invention, inorganic flame retardants such as magnesium hydroxide and aluminum hydroxide, halogen-based, organic flame retardants such as phosphorus-based, metal powder, antioxidant, ultraviolet ray inhibitor, Lubricants, dispersants, coupling agents, foaming agents, crosslinking agents, coloring agents, additives such as carbon black, other polyolefin resins, aromatic polyesters, polyphenylene ethers, polyamides, polycarbonates, Engineering plastics such as polyoxymethylene and polyphenylene sulfide, and vinyl resins such as polystyrene, ABS and polyvinyl chloride may be added.

[0033]

Since the thermoplastic resin of the present invention or its molded product has a functional group, it has excellent compatibility with metal or polar resin and excellent adhesiveness. Therefore, it is suitable for use in a laminate such as a laminate film. In addition, mechanical properties are maintained because of excellent film processability.

[0034]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. The abbreviations in the table are as follows. mPE: polyethylene synthesized by metallocene catalyst mPP: polypropylene synthesized by metallocene catalyst LDPE: low density polyethylene MAA: methacrylic acid GMA: glycidyl methacrylate HPMA: hydroxypropyl methacrylate DMA: dimethylacrylamide St: styrene AA: acrylic acid

Example 1 Into a stainless steel autoclave having a volume of 5 liters, 2500 g of pure water was added, and 2.5 g of polyvinyl alcohol was dissolved as a suspending agent. Polyethylene synthesized with a metallocene catalyst (number average molecular weight: 50,000)
0, measured by high temperature gel permeation chromatography) 800 g, 95 g of styrene and 95 g of acrylic acid
And stirred and dispersed. Next, the autoclave is set at 85.
The temperature was raised to ９０90 ° C., and the mixture was stirred for 2 hours to impregnate the vinyl monomer into the polyethylene. Next, the temperature of the autoclave was lowered to 80 ° C., and 1.5 g of benzoyl peroxide as a polymerization initiator, 4 g of t-butylperoxymethacryloyloxyethyl carbonate as a monomer containing a peroxide, 5 g of styrene, A mixed solution containing 5 g of an acid was charged and stirred in the autoclave.

The temperature of the autoclave was maintained at 80 ° C., and the temperature was maintained for 4 hours to complete the polymerization, followed by washing and drying to obtain a precursor. The styrene / acrylic acid copolymer in this precursor was extracted with toluene, and the number average molecular weight was measured by gel permeation chromatography to be 110,000.

Next, this precursor was extruded at 200 ° C. with a Labo Plastomill single-screw extruder (manufactured by Toyo Seiki Seisaku-sho, Ltd.) and a grafting reaction was carried out to obtain a thermoplastic resin as a graft copolymer. When this was analyzed by pyrolysis gas chromatography, the weight ratio of polyethylene: styrene: acrylic acid was 80: 10: 1.
It was 0. At this time, the graft efficiency of the styrene / acrylic acid copolymer segment was 50% by weight.

This thermoplastic resin was treated with a scanning electron microscope “J
Observation with "EOL JSM T300" (manufactured by JEOL Ltd.) revealed that the resin was a multilayer structure type thermoplastic resin in which spherical resins having a particle diameter of 0.3 to 0.4 [mu] m were uniformly dispersed.

(Film forming processability)
It was extruded at 200 ° C. with a Labo Plastomill single screw extruder equipped with a T-die at the tip to produce a film having a thickness of 100 μm. At this time, the moldability of the film was observed.
The judgment was made based on the following criteria. ：: A film can be smoothly formed. Δ: The film thickness is slightly varied. ×: Film thickness cannot be controlled or film production cannot be performed.

(Adhesion strength) First, a thickness of 10
A 0 μm aluminum plate is placed, a 100 μm thick thermoplastic resin film is placed thereon, and a 10 μm thick
An aluminum plate of 0 μm was overlaid.

After being put in a hot press at 210 ° C. while being sandwiched between press plates, and preheated for about 3 minutes, 100 kg /
The pressure was increased to cm ² , and the mixture was heated under pressure for 2 minutes. After depressurization, the press plate was taken out of the press machine, transferred to a cooling press maintained at 5 ° C., pressurized and cooled at 100 kg / cm ² for 5 minutes, depressurized, and a sample was taken out. The aluminum laminate obtained by the above operation was cut into strips having a width of 25 mm, and 300 mm in width.
When the T-peel test was performed at a speed of / min to measure the adhesive strength, it was 25 kgf / 25 mm.

Examples 2 to 10 The graft copolymerization was carried out in the same manner as in Example 1 except that the types of the olefin polymer and the vinyl monomer to be the olefin polymer segment were changed as shown in Tables 1 to 4. A combined thermoplastic resin was obtained. Further, the graft efficiency, the range of the particle diameter, the adhesive strength and the film forming workability were measured in the same manner as in Example 1, and the results are shown in Tables 1 to 4.

[0043]

[Table 1]

[0044]

[Table 2]

[0045]

[Table 3]

[0046]

[Table 4]

Comparative Example 1 The method of Example 1 was repeated except that the polyethylene synthesized with the metallocene catalyst of Example 1 was changed to a low-density polyethylene (number average molecular weight: 50,000, abbreviated as LDPE) synthesized with a titanium-based catalyst. To obtain a thermoplastic resin. Also,
In the same manner as in Example 1, the grafting efficiency, the range of the particle diameter,
The adhesive strength and film forming processability were measured, and the results are shown in Table 5.

[0048]

[Table 5]

Comparative Example 2 A thermoplastic resin was obtained in the same manner as in Example 1 except that acrylic acid as a polar vinyl monomer was not used. Further, the grafting efficiency, the range of the particle diameter, the adhesive strength and the film forming processability were measured in the same manner as in Example 1, and the results are shown in Table 5.

Comparative Example 3 (Production of random copolymer of styrene and acrylic acid) A stainless steel autoclave having a volume of 5 liters was charged with 25 pure water.
Of polyvinyl alcohol as a suspending agent.
2.5 g was dissolved. In this, styrene 500
g, a mixed solution of 500 g of acrylic acid and 7.5 g of benzoyl peroxide, raise the temperature to 80 ° C., maintain the temperature for 4 hours to complete the polymerization, wash and dry, and wash with styrene / acrylic acid random copolymer. I got The number average molecular weight of this random copolymer measured by GPC was 110,000. When the composition was analyzed by pyrolysis gas chromatography, the weight ratio of styrene: acrylic acid was 1: 1.

(Production of Blend Polymer) Then, 800 g of polyethylene synthesized with a metallocene catalyst and 200 g of a styrene / acrylic acid random copolymer were dry-blended, and the mixture was heated at 200 ° C. using a twin-screw extruder (manufactured by Ikegai Iron Works). Polyethylene melt-kneaded and synthesized with a metallocene catalyst:
A blend polymer having a weight ratio of styrene: acrylic acid of 80:10:10 was obtained. Observation of the blend polymer with a scanning electron microscope “JEOL JSM T300” (manufactured by JEOL Ltd.) revealed that the particle size was 20 to 1
It was 00 μm. Further, the graft efficiency, the adhesive strength and the film forming processability of this blended polymer were measured in the same manner as in Example 1, and the results are shown in Table 5.

Comparative Example 4 (Production of acid-modified polyethylene) 900 g of polyethylene synthesized with the metallocene catalyst used in Example 1 and toluene 60 were placed in a stainless steel autoclave having a capacity of 20 liters.
00g was added and dissolved at 160 ° C. Here, a toluene solution of acrylic acid (acrylic acid: 100 g, toluene: 10
00g) and a toluene solution of dicumyl peroxide (dicumyl peroxide: 1 g, toluene: 100 g) were added dropwise over 4 hours. After completion of the dropping, the reaction was further performed for 1 hour, and then cooled to room temperature, and the polymer was precipitated and collected by filtration. An attempt was made to form a film of this polymer in the same manner as in Example 1, but unreacted acrylic acid foamed and molding was difficult.

When Example 1 and Comparative Example 1 are compared, there is a difference in adhesive strength, and it is clear that the thermoplastic resin of the present invention has excellent adhesiveness. Further, when Examples 1 to 10 and Comparative Example 2 are compared, there is a difference in adhesive strength, and a thermoplastic resin not using acrylic acid, which is a polar vinyl monomer, is remarkably inferior in adhesiveness. Further, from Comparative Example 3, styrene / polystyrene was used instead of the copolymer having the specific structure of the present invention.
When the acrylic acid random copolymer is used, it is apparent that the graft efficiency, the range of the particle diameter, the adhesive strength, and the film forming processability are all remarkably inferior. Further, from Comparative Example 4, it is clear that the polymer grafted using the ordinary radical polymerization initiator has poor moldability.

 ────────────────────────────────────────────────── ─── Continued on the front page F-term (reference) 4F100 AB10B AK03A AK04A AK04J AK12A AK12J AK25A AK25J AL04A AR00B BA02 BA03 BA06 JA07A JG10B JK11 4J002 BB03W BB05W BB12W BA14BA05BA08A13 BA18A BA18A BA27 BA28 BA29 BA30 BA32 BA34 BA35 BB02 BB08 CA10 DB07 DB13 DB32 EA05 GA01 HA06 HA11 HA35 HA38 HE04

Claims (4)

[Claims] 1. An olefin polymer segment having a number average molecular weight of 5,000 to 1,000,000 synthesized by a metallocene catalyst, 30 to 99% by weight, and at least one vinyl containing a polar vinyl monomer. A graft copolymer comprising 1 to 70% by weight of a vinyl (co) polymer segment having a number average molecular weight of 400 to 1,000,000 formed from a series monomer, wherein one segment is the other segment. A multi-phase structure type thermoplastic resin dispersed with a particle size of 0.001 to 10 μm. 2. An aqueous suspension of particles comprising an olefin polymer synthesized with a metallocene catalyst, one or more vinyl monomers including a polar vinyl monomer, And a radical polymerization initiator, and heating under conditions where decomposition of the radical polymerization initiator does not substantially occur, and one or more vinyl monomers including the polar vinyl monomer, peroxide After the bond-containing monomer and the radical polymerization initiator are impregnated into the particles of the olefin polymer, the aqueous suspension is decomposed by this radical suspension, and the peroxide-containing monomer is peroxided. The temperature is raised to a temperature at which the bond is not substantially decomposed, and one or more vinyl monomers including the polar vinyl monomer and a peroxide bond-containing monomer are copolymerized in the olefin polymer particles. A first step of obtaining a grafted precursor to be polymerized; And kneading the grafted precursor under melting at a temperature at which a peroxide bond derived from a peroxide bond-containing monomer is decomposed to obtain a graft copolymer. The thermoplastic resin described in the above. 3. A molded article obtained by molding the thermoplastic resin according to claim 1 or 2. 4. The molded article according to claim 3, wherein the molded article is a laminate with a polar material.