Method for producing acid-modified polyolefin resin using co-rotating multi-screw extruder

Abstract

The present disclosure provides a method for producing an acid-modified polyolefin resin using a co-rotating multi-screw extruder, the method being capable of preventing backflow of the raw material even when the amount of raw material charged is increased, and having excellent operational stability. Specifically, the present disclosure provides a method for producing an acid-modified polyolefin resin using a co-rotating multi-screw extruder, the method including: a step (A) for mixing, in a raw material mixing unit, a raw material containing a polyolefin resin and an alpha, beta-unsaturated carboxylic acid and / or an acid anhydride thereof; a step (B) for conveying the mixture obtained in step (A) to a reaction unit by a conveyance unit; a step (C) for reacting the conveyed mixture in the reaction unit to obtain a graft polymer of the polyolefin resin and the alpha, beta-unsaturated carboxylic acid and / or the acid anhydride thereof; a step (D) for devolatilizing the graft polymer in a devolatilization unit; and a step (E) for cooling the devolatilized graft polymer in an adjustment unit.

Description

Method for producing acid-modified polyolefin resin using a co-directional multi-screw extruder

[0001] This disclosure relates to a method for producing acid-modified polyolefin resin using a coaxial multi-screw extruder.

[0002] Traditionally, polyolefin resins such as polypropylene and polyethylene have been widely used as materials in fields such as automotive parts, electrical components, building materials, and packaging films because they are relatively inexpensive and possess excellent properties such as chemical resistance, water resistance, and heat resistance.

[0003] On the other hand, polyolefin resins generally have high crystallinity and low polarity, which can make them difficult for paints, printing inks, adhesives, etc., to adhere to.

[0004] Therefore, acid-modified polyolefin resins, which are graft-modified using unsaturated carboxylic acids, acid anhydrides of unsaturated carboxylic acids, etc., have been proposed as adhesives.

[0005] A widely known method for producing acid-modified polyolefin resins is the use of a multi-screw extruder.

[0006] For example, Patent Document 1 describes a method for producing a modified polyolefin resin composition using a coaxial twin-screw extruder, wherein a polyolefin resin is grafted with an unsaturated carboxylic acid derivative and / or its anhydride in an amount of 1 to 90% by weight, and the weight-average molecular weight is 15,000 to 200,000, characterized in that the temperature of the reaction section, which is a component of the extruder, is 150 to 230°C, and the length of the reaction section accounts for 25% to 55% of the total length L of the extruder.

[0007] Patent Document 2 describes a method for producing a modified polyolefin resin using a coaxial multi-screw extruder, wherein the graft weight of at least one modifying component selected from the group consisting of unsaturated carboxylic acids, their anhydrides, and unsaturated carboxylic acid derivatives to the polyolefin resin is 0.1 to 20% by weight, and the weight-average molecular weight is 5,000 to 300,000, and the raw materials containing the polyolefin resin and the modifying component, which are fed into the coaxial multi-screw extruder, are extruded as the modified polyolefin resin through each barrel in the order of raw material mixing section, melt-kneading section, reaction section, and defoliation-cooling section, and the barrel temperature of the raw material mixing section is set to 40 to 60°C.

[0008] Patent Document 3 describes a method for producing a modified polyolefin resin using a coaxial multi-screw extruder, wherein the graft weight of at least one modifying component selected from the group consisting of unsaturated carboxylic acids, their anhydrides, and unsaturated carboxylic acid derivatives is 0.1 to 20% by weight, and the weight-average molecular weight is 5,000 to 300,000, and the modified polyolefin resin is prepared using a coaxial multi-screw extruder, wherein the raw materials containing the polyolefin resin and the modifying component, which are fed into the coaxial multi-screw extruder, are extruded as the modified polyolefin resin through each barrel in the order of raw material mixing section, melt kneading section, reaction section, and devolatilization cooling section, and the barrel temperature of the vent section in the devolatilization cooling section is set to 70 to 150°C.

[0009] Japanese Patent Publication No. 2004-114610, Japanese Patent Publication No. 2021-155584, Japanese Patent Publication No. 2021-167363

[0010] The manufacturing method described in Patent Document 1 has poor operational stability because it cannot prevent backflow of raw materials and a large amount of unreacted modified components remain.

[0011] The manufacturing methods described in Patent Documents 2 and 3 suffer from poor operational stability because, when the amount of raw material input is increased, it is not possible to prevent backflow of the raw material.

[0012] The present disclosure aims to provide a method for producing acid-modified polyolefin resin using a coaxial multi-screw extruder that can prevent backflow of raw materials even when the amount of raw material input is increased, and that has excellent operational stability.

[0013] The inventors, through diligent research to achieve the above objective, discovered that this objective could be achieved by using a coaxial multi-screw extruder having a specific structure and satisfying specific parameters. This disclosure is the result of further research and completion.

[0014] This disclosure includes the subject matter set forth in the following sections: Section 1. A method for producing an acid-modified polyolefin resin using a coaxial multi-screw extruder, comprising: (A) mixing a raw material containing a polyolefin resin and an α,β-unsaturated carboxylic acid and / or its acid anhydride in a raw material mixing section; (B) transporting the mixture obtained in step (A) to a reaction section in a transport section; (C) reacting the transported mixture in the reaction section to obtain a graft polymer of the polyolefin resin and the α,β-unsaturated carboxylic acid and / or its acid anhydride; (D) defoliating the graft polymer in a defoliation section; and (E) cooling the defoliated graft polymer in a adjustment section, wherein the melting point of the acid-modified polyolefin resin is 60 to 160°C, the graft amount of the α,β-unsaturated carboxylic acid and / or its acid anhydride in the acid-modified polyolefin resin is 0.1 to 20% by mass, and the weight-average molecular weight of the acid-modified polyolefin resin is 5,000 to 300,000. A method for producing an acid-modified polyolefin resin using a coaxial multi-screw extruder, wherein the barrel temperature of the raw material mixing section is 15°C or higher and 40°C or lower, and the raw material input amount Q, the screw rotation speed Ns of the reaction section, and the screw diameter D of the reaction section satisfy the following formula (1). 15 ≤ Q / (Ns × D ３ ) ≤ 40 (1)

[0015] The method for producing acid-modified polyolefin resin using a coaxial multi-screw extruder as disclosed herein can prevent backflow of raw materials even when a large amount of raw material is input, and offers excellent operational stability.

[0016] Preferred embodiments of this disclosure are described in detail below. The descriptions of constituent elements below may be based on representative embodiments and specific examples, but this disclosure is not limited to such embodiments.

[0017] In this disclosure, the expressions “contains” and “includes” include the concepts of “contains,” “includes,” “substantially consists of,” and “consistes of only.”

[0018] In the numerical ranges described in stages in this disclosure, the upper or lower limit of one stage of the numerical range can be arbitrarily combined with the upper or lower limit of another stage of the numerical range. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with values ​​shown in the examples or values ​​that can be uniquely derived from the examples.

[0019] In this disclosure, the phrase "any number A to any number B" means number A and a range greater than number A, and number B and a range less than number B.

[0020] In this disclosure, “A and / or B” means “either A or B” or “both A and B,” and more specifically, “A,” “B,” or “A and B.”

[0021] In this disclosure, gauge pressure refers to relative pressure with respect to atmospheric pressure (0.1013 MPa), and means the pressure difference obtained by subtracting atmospheric pressure from absolute pressure. In this disclosure, gauge pressure is expressed with a "G" prefix, for example, MPaG.

[0022] In this disclosure, the graft amount of α,β-unsaturated carboxylic acid and / or its acid anhydride in the acid-modified polyolefin resin means the content of α,β-unsaturated carboxylic acid and / or the content of α,β-unsaturated carboxylic acid acid anhydride (mass%) in the acid-modified polyolefin resin.

[0023] In this disclosure, the graft amount of α,β-unsaturated carboxylic acid and its acid anhydride in the acid-modified polyolefin resin means the total amount (mass%) of the graft amount of α,β-unsaturated carboxylic acid and the graft amount of the acid anhydride of the α,β-unsaturated carboxylic acid in the acid-modified polyolefin resin.

[0024] The method for producing the acid-modified polyolefin resin according to this disclosure is characterized by using a coaxial multi-screw extruder.

[0025] (Co-direction multi-screw extruder) In this disclosure, a co-direction multi-screw extruder typically comprises a raw material mixing section, a conveying section, a reaction section, a devolatilization section, and a conditioning section. In this disclosure, the co-direction multi-screw extruder is preferably a co-direction twin-screw extruder, a co-direction tri-screw extruder, or a co-direction quad-screw extruder, and more preferably a co-direction twin-screw extruder.

[0026] In this disclosure, the total length of the barrels of the raw material mixing section, the conveying section, the reaction section, the devolatilization section, and the adjustment section is preferably 70% or more, more preferably 75% or more, even more preferably 80% or more, even more preferably 85% or more, and particularly preferably 90% or more, of the total length of the coaxial multi-screw extruder.

[0027] (Method for producing acid-modified polyolefin resin using a co-directional multi-screw extruder) The method for producing acid-modified polyolefin resin using a co-directional multi-screw extruder according to the present disclosure has the following configurations (I) to (VI). (I) A step (A) of mixing raw materials containing a polyolefin resin and an α,β-unsaturated carboxylic acid and / or its acid anhydride in a raw material mixing section; a step (B) of transporting the mixture obtained in step (A) to a reaction section in a transport section; a step (C) of reacting the transported mixture in the reaction section to obtain a graft polymer of the polyolefin resin and the α,β-unsaturated carboxylic acid and / or its acid anhydride; a step (D) of deflorating the graft polymer in a defloration section; and a step (E) of cooling the deflorated graft polymer in a adjustment section. (II) The barrel temperature of the raw material mixing section is 15°C or higher and 40°C or lower. (III) The raw material input amount Q, the screw rotation speed Ns of the reaction section, and the screw diameter D of the reaction section satisfy the following formula (1). 15 ≤ Q / (Ns × D) ３) ≤ 40 (1) (IV) The melting point of the acid-modified polyolefin resin obtained through the above steps (A) to (E) is 60 to 160°C. (V) The grafting amount of α,β-unsaturated carboxylic acid and / or acid anhydride thereof in the acid-modified polyolefin resin obtained through the above steps (A) to (E) is 0.1 to 20% by mass. (VI) The weight average molecular weight of the acid-modified polyolefin resin obtained through the above steps (A) to (E) is 5,000 to 300,000.

[0028] Hereinafter, the method for producing an acid-modified polyolefin resin using the same-direction multi-screw extruder of the present disclosure is also referred to as the "production method of the present disclosure".

[0029] In the production method of the present disclosure, the barrel temperature of the raw material mixing section is 15°C or higher and 40°C or lower. Therefore, the raw material containing the polyolefin resin fed into the raw material mixing section, and α,β-unsaturated carboxylic acid and / or its acid anhydride does not completely melt, passes through the raw material mixing section and the conveying section while maintaining the shape of the raw material, and is supplied to the reaction section. By supplying the raw material to the reaction section while maintaining its shape, it is possible to perform graft polymerization with high shearing force in a state where the resin viscosity is high in the reaction section. In addition, since the barrel temperature of the raw material mixing section is 15°C or higher and 40°C or lower, feedback (backflow of the raw material) can be prevented even when the raw material input amount is increased during raw material feeding.

[0030] Hereinafter, steps (A), (B), (C), (D) and (E) in the production method of the present disclosure will be described in detail.

[0031] In the production method of the present disclosure, it is preferable to perform step (A), step (B), step (C), step (D) and step (E) in this order.

[0032] <Step (A)> Step (A) of the present disclosure is a step of obtaining a mixture by mixing a raw material containing a polyolefin resin and α,β-unsaturated carboxylic acid and / or an acid anhydride thereof in a raw material mixing section. The mixture obtained in step (A) of the present disclosure is supplied to the conveying section.

[0033] In step (A) of the present disclosure, the raw materials preferably include a polyolefin resin, an α,β-unsaturated carboxylic acid and / or its acid anhydride, and a radical generator.

[0034] In step (A) of the present disclosure, the raw materials more preferably include a polyolefin resin, an α,β-unsaturated carboxylic acid anhydride, and a radical generator.

[0035] In step (A) of the present disclosure, the amount of α,β-unsaturated carboxylic acid and / or its acid anhydride used is preferably 0.2 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of polyolefin resin, from the viewpoint of efficiently advancing graft polymerization.

[0036] In step (A) of this disclosure, if the raw material contains a radical generator, the amount of radical generator used is preferably 0.5 to 5 parts by mass per 100 parts by mass of polyolefin resin, from the viewpoint of efficiently promoting graft polymerization.

[0037] In step (A) of the present disclosure, the barrel temperature of the raw material mixing section is preferably 15°C or higher and less than 40°C, more preferably 16°C or higher and 39°C or lower.

[0038] In step (A) of the present disclosure, the barrel length of the raw material mixing section is preferably 3 to 15% of the overall length of the coaxial multi-screw extruder, and more preferably 5 to 10% of the overall length of the coaxial multi-screw extruder.

[0039] In step (A) of the present disclosure, the screw configuration of the raw material mixing section preferably consists mainly of screw elements, and more preferably mainly of general-purpose shallow groove type and / or deep groove type screw elements.

[0040] In this disclosure, "screw element" means a screw and / or reverse screw. In a screw element, the number of threads of the element is usually one, two, three, or four, preferably two or three. In a screw element, the depth of the element's valley is preferably 0.5 to 0.7 when expressed as the ratio of valley diameter to peak diameter. Setting it within this range tends to result in better conveying capacity. From the viewpoint of increasing the variations in screw element combinations, the L / D (element length / diameter) of each element is preferably 2.0 or less.

[0041] (Polyolefin resins) In this disclosure, polyolefin resins are, for example, homopolymers of α-olefins having 2 to 20 carbon atoms (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20), such as ethylene, propylene, 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, or copolymers of two or more of these; Examples include homopolymers of linear or cyclic polyenes such as cyclopentene, cyclohexene, 1,4-hexadiene, 1,5-hexadiene, divinylbencene, 1,3-cyclopentadiene, 1,3-cyclohexadiene, and 5-vinyl-2-norbornene, or copolymers of two or more of these; and homopolymers of styrene monomers such as styrene and substituted styrenes (α-methylstyrene, β-methylstyrene, p-methylstyrene, etc.), or copolymers of two or more of these. In this disclosure, the proportion of these monomers in the polyolefin resin can be arbitrarily selected.

[0042] In this disclosure, the polyolefin resin preferably has structural units derived from α-olefins. In this disclosure, the polyolefin resin may be an olefin polymer containing one type of structural unit derived from α-olefins, a copolymer of an olefin polymer containing two types of structural units derived from α-olefins, or a copolymer of an olefin polymer containing three or more types of structural units derived from α-olefins.

[0043] In this disclosure, the polyolefin resin is preferably at least one selected from the group consisting of homopolyethylene (a homopolymer of ethylene), homopolypropylene (a homopolymer of propylene), and propylene-α-olefin copolymer, and more preferably a propylene-α-olefin copolymer.

[0044] In this disclosure, the propylene-α-olefin copolymer is obtained by copolymerizing propylene with an α-olefin. Examples of the α-olefin include ethylene, 1-butene, 1-heptene, 1-octene, 4-methyl-1-pentene, vinyl acetate, etc., and these can be used individually or in combination of two or more.

[0045] In one embodiment of the present disclosure, the propylene-α-olefin copolymer is preferably a propylene-ethylene copolymer, a propylene-1-butene copolymer, or a propylene-ethylene-1-butene copolymer.

[0046] In one embodiment of the present disclosure, the content of the propylene component in the propylene-α-olefin copolymer is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, and particularly preferably 75 mol% or more.

[0047] (α,β-unsaturated carboxylic acids and / or acid anhydrides thereof) Examples of α,β-unsaturated carboxylic acids and / or acid anhydrides thereof in this disclosure include maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, mesaconic acid, citraconic acid, citraconic anhydride, aconitic acid, aconitic anhydride, and the like.

[0048] In this disclosure, the α,β-unsaturated carboxylic acid and / or its acid anhydride is preferably an acid anhydride of an α,β-unsaturated carboxylic acid, more preferably maleic anhydride, itaconic anhydride, citraconic anhydride, or aconitic anhydride, and even more preferably maleic anhydride.

[0049] In this disclosure, other unsaturated monomers such as (meth)acrylic acid, maleimide, N-phenylmaleimide, and isocyanate-containing (meth)acrylates may be used in combination with α,β-unsaturated carboxylic acids and / or their acid anhydrides, depending on the application and purpose. In this disclosure, from the viewpoint of obtaining the desired adhesion of the acid-modified polyolefin resin, it is preferable that the amount of the other unsaturated monomer used does not exceed the amount of α,β-unsaturated carboxylic acid and / or its acid anhydride used.

[0050] (Radical Generator) In this disclosure, the radical generator is preferably an organic peroxide. Examples of organic peroxides include peroxides such as di-tert-butyl peroxyphthalate, tert-butyl hydroperoxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxypivalate, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, di-tert-butyl peroxide, and lauroyl peroxide; and azonitrile compounds such as azobisisobutyronitrile and azobisisopropionitrile. These can be used individually or in combination of two or more.

[0051] In this disclosure, the radical generator is more preferably di-tert-butyl peroxide.

[0052] <Process (B)> Process (B) of this disclosure is a process of transporting the mixture obtained in process (A) to the reaction section using a transport section. The transport section is a part that further mixes the mixture obtained in process (A) while transporting it, and then transports it to the reaction section.

[0053] In step (B) of the present disclosure, the barrel temperature of the conveying section is preferably 20°C or more and 60°C or less, more preferably 20°C or more and less than 60°C, even more preferably 25°C or more and less than 60°C, and still more preferably 30°C or more and less than 60°C.

[0054] In step (B) of the present disclosure, the barrel length of the conveying section is preferably 3 to 20% of the overall length of the coaxial multi-screw extruder, and more preferably 5 to 15% of the overall length of the coaxial multi-screw extruder.

[0055] In step (B) of this disclosure, the screw configuration of the conveying section preferably consists mainly of screw elements, and more preferably mainly of general-purpose shallow groove type and / or deep groove type screw elements. As necessary, kneading elements described later can also be used as the screw configuration of the conveying section.

[0056] In this disclosure, "screw element" means a screw and / or reverse screw. In a screw element, the number of threads of the element is usually one, two, three, or four, preferably two or three. In a screw element, the depth of the element's root is preferably 0.5 to 0.7 when expressed as the ratio of root diameter to crest diameter. Setting it within this range tends to result in better conveying capacity. From the viewpoint of increasing the variations in screw element combinations, the L / D (element length / diameter) of each element is preferably 2.0 or less.

[0057] <Step (C)> Step (C) of the present disclosure is a step of reacting the mixture transported in step (B) in a reaction section to obtain a graft polymer of a polyolefin resin and an α,β-unsaturated carboxylic acid and / or its acid anhydride.

[0058] The reaction in step (C) of this disclosure is typically a graft reaction.

[0059] The graft polymer of step (C) of this disclosure typically has a structure in which α,β-unsaturated carboxylic acid and / or its acid anhydride are graft-polymerized onto a polyolefin resin.

[0060] In step (C) of this disclosure, the details of the polyolefin resin and the α,β-unsaturated carboxylic acid and / or its acid anhydride are as described in step (A) above, unless otherwise specified.

[0061] In step (C) of the present disclosure, the barrel temperature of the reaction section is preferably 65°C to 210°C, more preferably 70°C to 180°C, even more preferably 75°C to 150°C, and still more preferably 80°C to less than 120°C.

[0062] In step (C) of the present disclosure, the barrel length of the reaction section is preferably 25 to 55% of the overall length of the coaxial multi-screw extruder, and more preferably 30 to 50% of the overall length of the coaxial multi-screw extruder.

[0063] In step (C) of the present disclosure, the screw configuration of the reaction section is, for example, a screw element, a kneading disc, a mixing screw, or a reverse mixing screw, which can be used individually or in combination of two or more.

[0064] In this disclosure, "screw element" means a screw and / or reverse screw. In a screw element, the number of threads of the element is usually one, two, three, or four, preferably two or three. The depth of the root of the element is preferably 0.5 to 0.7 when expressed as the ratio of root diameter to crest diameter. Setting it within this range tends to result in better conveying capacity.

[0065] In this disclosure, "kneading disc" means a kneading disc right in which multiple paddle-shaped discs are overlapped with a rightward shift; a kneading disc left in which multiple paddle-shaped discs are overlapped with a leftward shift; a kneading disc neutral in which paddle-shaped discs are overlapped with a 90-degree shift; a mixing screw with notched screw threads; and a reverse mixing screw. In a kneading disc, the number of threads on the element is usually one, two, three, or four, preferably two or three.

[0066] In step (C) of the present disclosure, the screw configuration of the reaction section preferably includes a kneading disc. In step (C) of the present disclosure, the occupancy of the kneading discs in the screw configuration of the reaction section is more preferably 65 to 100%.

[0067] In step (C) of the present disclosure, when the screw configuration of the reaction section includes a kneading disc, the kneading disc is preferably composed of a right-hand kneading disc, a left-hand kneading disc and a neutral kneading disc.

[0068] In the configuration of the kneading discs, the occupancy of the right-hand kneading discs is preferably 40 to 60%.

[0069] In the configuration of the kneading discs, the occupancy of the neutral kneading discs is preferably 35 to 55%.

[0070] In the present disclosure, when the raw material input amount is Q (kg / h), the screw rotation speed of the reaction section is Ns (rpm), and the screw diameter of the reaction section is D (mm), Q / (Ns×D ３ ) satisfies the following formula (1). Note that the unit of Q / (Ns×D ３ ) is kg / m ３ 15≦Q / (Ns×D ３ )≦40 (1)

[0071] In step (C) of the present disclosure, when the screw configuration of the reaction section includes a kneading disc, in the above formula (1), the screw rotation speed Ns (rpm) of the reaction section means the rotation speed (rpm) of the kneading disc in the reaction section, and the screw diameter D (mm) of the reaction section means the diameter D (mm) of the kneading disc in the reaction section.

[0072] In the present disclosure, Q / (Ns×D ３ ) is 15 (kg / m ３ ) or more and 40 or less (kg / m ３ ), whereby the production method of the present disclosure can prevent reverse flow of the raw material even when the raw material input amount is increased during raw material feeding, and is excellent in operational stability.

[0073] In formula (1) of this disclosure, preferably 16 ≤ Q / (Ns × D ３ ) ≤ 39, more preferably 17 ≤ Q / (Ns × D ３ ) ≤ 38, more preferably 18 ≤ Q / (Ns × D ３ ) ≤ 37.

[0074] In this disclosure, the screw rotation speed Ns of the reaction section is preferably 300 to 1500 rpm, more preferably 350 to 1300 rpm, and even more preferably 400 to 1100 rpm.

[0075] In this disclosure, the raw material input amount Q is preferably 5 to 500 kg / h, more preferably 10 to 400 kg / h, and even more preferably 15 to 300 kg / h.

[0076] In this disclosure, the screw diameter D of the reaction section is preferably 15 mm or more and 100 mm or less, more preferably 20 mm or more and 90 mm or less, and even more preferably 25 mm or more and 80 mm or less.

[0077] <Step (D)> Step (D) of this disclosure is a step of defoliating the graft polymer obtained in step (C) in a defoliation section. In this disclosure, the defoliation section is a section that removes low molecular weight volatile components from the graft polymer obtained in step (C). In the defoliation section, the barrel temperature and the degree of reduced pressure are usually adjusted to the boiling point of the volatile components. In the defoliation section, the graft polymer obtained in step (C) may be defoliated stepwise. If defoliation in the defoliation section is insufficient, it may affect the physical properties, odor, solution properties, etc. of the acid-modified polyolefin resin.

[0078] In step (D) of this disclosure, the barrel temperature of the evaporator section is preferably 150°C or higher and 200°C or lower.

[0079] In step (D) of the present disclosure, the barrel length of the devolatilization section is preferably 30 to 20% of the overall length of the coaxial multi-screw extruder, and more preferably 5 to 15% of the overall length of the coaxial multi-screw extruder.

[0080] In step (D) of the present disclosure, the degree of reduced pressure in the evaporative section is preferably -0.096 MPaG or more and -0.040 MPaG or less, more preferably -0.096 MPaG or more and -0.060 MPaG or less.

[0081] In step (D) of the present disclosure, the screw configuration of the detachment section preferably consists mainly of screw elements, and more preferably mainly of general-purpose shallow groove type and / or deep groove type screw elements.

[0082] In this disclosure, "screw element" means a screw and / or reverse screw. In a screw element, the number of threads of the element is usually one, two, three, or four, preferably two or three. In a screw element, the depth of the element's root is preferably 0.5 to 0.7 when expressed as the ratio of root diameter to crest diameter. Setting it within this range tends to result in better conveying capacity. From the viewpoint of increasing the variations in screw element combinations, the L / D (element length / diameter) of each element is preferably 2.0 or less.

[0083] <Step (E)> Step (E) of this disclosure is a step of cooling the graft polymer defolable in step (D) in a conditioning unit. In this disclosure, if the defolable graft polymer is not cooled sufficiently in the conditioning unit, the acid-modified polyolefin resin extruded by the strand may become sticky, making it impossible to cut with the cutting machine. In this disclosure, "cooling in the conditioning unit" means adjusting the defolable graft polymer to a temperature at which it can be solidified.

[0084] In step (E) of the present disclosure, the barrel temperature of the adjustment section is preferably 20°C to 210°C, more preferably 50°C to 210°C, even more preferably 75°C to 210°C, and particularly preferably 100°C to 210°C.

[0085] In step (E) of the present disclosure, the barrel length of the adjustment section is preferably 20 to 40% of the overall length of the coaxial multi-screw extruder, and more preferably 25 to 35% of the overall length of the coaxial multi-screw extruder.

[0086] In step (E) of the present disclosure, the screw configuration of the adjustment section preferably consists mainly of screw elements, and more preferably mainly of general-purpose shallow groove type and / or deep groove type screw elements.

[0087] In this disclosure, "screw element" means a screw and / or reverse screw. In a screw element, the number of threads of the element is usually one, two, three, or four, preferably two or three. In a screw element, the depth of the root is preferably 0.5 to 0.7 when expressed as the ratio of root diameter to crest diameter. Setting it within this range tends to result in better conveying capacity. From the viewpoint of increasing the variations in screw element combinations, the L / D (element length / diameter) of each element is preferably 2.0 or less.

[0088] In this disclosure, the residence time of the raw material in the entire coaxial multi-screw extruder is preferably 5 to 300 seconds, more preferably 20 to 120 seconds.

[0089] (Acid-Modified Polyolefin Resin) The acid-modified polyolefin resin obtained by the manufacturing method of this disclosure will be described in detail below. Hereinafter, the acid-modified polyolefin resin obtained by the manufacturing method of this disclosure will also be referred to as "the acid-modified polyolefin resin of this disclosure".

[0090] The melting point of the acid-modified polyolefin resin of this disclosure is 60 to 160°C. Preferably, the melting point of the acid-modified polyolefin resin of this disclosure is 62 to 150°C, and more preferably 64 to 140°C.

[0091] The amount of α,β-unsaturated carboxylic acid and / or its acid anhydride grafted in the acid-modified polyolefin resin of this disclosure is 0.1 to 20% by mass. Preferably, the amount of α,β-unsaturated carboxylic acid and / or its acid anhydride grafted in the acid-modified polyolefin resin of this disclosure is 0.4 to 15% by mass, more preferably 0.6 to 10% by mass, even more preferably 0.8 to 5.0% by mass, and still more preferably 1.0 to 4.0% by mass.

[0092] The weight-average molecular weight of the acid-modified polyolefin resin of this disclosure is 5,000 to 300,000. Preferably, the weight-average molecular weight of the acid-modified polyolefin resin of this disclosure is 10,000 to 250,000, more preferably 20,000 to 200,000, and even more preferably 30,000 to 150,000.

[0093] In the manufacturing method of the present disclosure, it is preferable that, in order to improve reaction efficiency, the rate of reduction in the amount of graft calculated by the following formula (2) is 30% or less when the acid-modified polyolefin resin is purified by the purification method described below. Graft amount reduction rate (%) = [(X - Y) / X] × 100 (2) (In equation (2), X represents the amount of α,β-unsaturated carboxylic acid grafts and / or the amount of α,β-unsaturated carboxylic acid acid anhydrides grafted in the acid-modified polyolefin resin before purification, as measured using a Fourier transform infrared spectrophotometer, and Y represents the amount of α,β-unsaturated carboxylic acid grafts and / or the amount of α,β-unsaturated carboxylic acid acid anhydrides grafted in the acid-modified polyolefin resin after purification, as measured using a Fourier transform infrared spectrophotometer.) [Method for purifying acid-modified polyolefin resin] 50 g of freeze-pulverized acid-modified polyolefin resin is weighed onto cylindrical filter paper and placed in a Soxhlet extraction tube. A condenser is attached to a flat-bottom flask containing 1100 mL of acetone, and the resin is refluxed in a water bath at the boiling point of acetone for 2 hours to extract it with acetone. Subsequently, the acid-modified polyolefin resin is removed from the cylindrical filter paper and purified by vacuum drying at 100°C for 1 hour.

[0094] In the manufacturing method of this disclosure, it is preferable that when the acid-modified polyolefin resin is purified by the purification method described below, the reduction rate of the graft amount calculated by the following formula (2) is 30% or less. Graft amount reduction rate (%) = [(X - Y) / X] × 100 (2) (In equation (2), X represents the amount of α,β-unsaturated carboxylic acid grafted and / or the amount of α,β-unsaturated carboxylic acid acid anhydride grafted in the acid-modified polyolefin resin before purification, calculated by the calculation method below, and Y represents the amount of α,β-unsaturated carboxylic acid grafted and / or the amount of α,β-unsaturated carboxylic acid acid anhydride grafted in the acid-modified polyolefin resin after purification, calculated by the calculation method below.) [Method for purifying acid-modified polyolefin resin] 50 g of freeze-pulverized acid-modified polyolefin resin is weighed onto cylindrical filter paper and placed in a Soxhlet extraction tube. A condenser is attached to a flat-bottom flask containing 1100 mL of acetone, and the resin is refluxed in a water bath at the boiling point of acetone for 2 hours to extract it with acetone. After that, the acid-modified polyolefin resin in the cylindrical filter paper is removed and purified by drying under reduced pressure at 100°C for 1 hour. [Method for calculating the amount of α,β-unsaturated carboxylic acid grafts in acid-modified polyolefin resin before and after purification] Using a Fourier transform infrared spectrophotometer (FT-IR) (FT-IR8200PC manufactured by Shimadzu Corporation), the coefficient (f) obtained from calibration curves prepared with chloroform solutions of α,β-unsaturated carboxylic acid at concentrations of 0.1 mass / volume percent, 0.05 mass / volume percent, and 0.0125 mass / volume percent is used, and the stretching peak (1710 cm) of the carbonyl (C=O) bond of the α,β-unsaturated carboxylic acid in the acid-modified polyolefin resin solution (a mixed solution consisting of acid-modified polyolefin resin and chloroform) is used. －１The absorbance (I) of ) was used and calculated by the following formula (i): Acid value (mgKOH / g-resin) = [Absorbance (I) × coefficient (f) × 2 × molecular weight of potassium hydroxide × 1000 (mg) / molecular weight of α,β-unsaturated carboxylic acid] ... formula (i) [In formula (i), the molecular weight of potassium hydroxide is 56.11. [Method for calculating the amount of grafted α,β-unsaturated carboxylic acid anhydride in acid-modified polyolefin resin before and after purification] Using a Fourier transform infrared spectrophotometer (FT-IR) (FT-IR8200PC manufactured by Shimadzu Corporation), the coefficient (f) obtained from calibration curves prepared with chloroform solutions of α,β-unsaturated carboxylic acid anhydride at concentrations of 0.1 mass / volume percent, 0.05 mass / volume percent, and 0.0125 mass / volume percent, and the expansion peak (1780 cm) of the carbonyl (C=O) bond of the α,β-unsaturated carboxylic acid anhydride in the acid-modified polyolefin resin solution (a mixed solution consisting of acid-modified polyolefin resin and chloroform) is calculated. －１ The acid value (mgKOH / g-resin) was calculated using the absorbance (I) of the α,β-unsaturated carboxylic acid acid anhydride and the following formula (i): Acid value (mgKOH / g-resin) = [Absorbance (I) × Coefficient (f) × 2 × Molecular weight of potassium hydroxide × 1000 (mg) / Molecular weight of α,β-unsaturated carboxylic acid acid anhydride] ... Formula (i) [In formula (i), the molecular weight of potassium hydroxide is 56.11.]

[0095] In the manufacturing method of the present disclosure, it is more preferable that the reduction rate of the graft amount calculated by the following formula (2A) is 30% or less when the acid-modified polyolefin resin is purified by the purification method described below. Graft amount reduction rate (%) = [(X1 - Y1) / X1] × 100 (2A) (In formula (2A), X1 represents the amount of graft of α,β-unsaturated carboxylic acid anhydride in the acid-modified polyolefin resin before purification, calculated by the calculation method described below, and Y1 represents the amount of graft of α,β-unsaturated carboxylic acid anhydride in the acid-modified polyolefin resin after purification, calculated by the calculation method described below.) [Method for purifying acid-modified polyolefin resin] 50 g of acid-modified polyolefin resin is weighed onto cylindrical filter paper and placed in a Soxhlet extraction tube. A condenser is attached to a flat-bottom flask containing 1100 mL of acetone, and the resin is refluxed in a water bath at the boiling point of acetone for 2 hours to perform acetone extraction. Subsequently, the acid-modified polyolefin resin is removed from the cylindrical filter paper and purified by vacuum drying at 100°C for 1 hour. [Method for calculating the amount of grafted α,β-unsaturated carboxylic acid anhydride in the acid-modified polyolefin resin before and after purification] Using a Fourier transform infrared spectrophotometer (FT-IR) (FT-IR8200PC manufactured by Shimadzu Corporation), the coefficient (f) obtained from calibration curves prepared with chloroform solutions of α,β-unsaturated carboxylic acid anhydride at concentrations of 0.1 mass / volume percent, 0.05 mass / volume percent, and 0.0125 mass / volume percent is used, and the coefficient (f) obtained from the calibration curve is used, and the carbonyl (C=O) bond stretching peak (1780 cm) of the α,β-unsaturated carboxylic acid anhydride in the acid-modified polyolefin resin solution (a mixed solution consisting of acid-modified polyolefin resin and chloroform) is used. －１ The absorbance (I) of ) was used to calculate the acid value using the following formula (i): Acid value (mgKOH / g-resin) = [Absorbance (I) × Coefficient (f) × 2 × Molecular weight of potassium hydroxide × 1000 (mg) / Molecular weight of α,β-unsaturated carboxylic acid anhydride] ... Formula (i) [In formula (i), the molecular weight of potassium hydroxide is 56.11.]

[0096] In this disclosure, the reduction rate of the graft amount calculated by formula (2) or formula (2A) is more preferably 28% or less, even more preferably 26% or less, even more preferably 24% or less, and particularly preferably 22% or less.

[0097] (Other configurations of the co-directional multi-screw extruder) The co-directional multi-screw extruder of this disclosure may include other configurations besides the raw material mixing unit, conveying unit, reaction unit, devolatilization unit, and adjustment unit, as needed.

[0098] Other components in this disclosure include, for example, a stirrer for powdering the raw materials; a feeder, hopper, or side feeder or liquid addition device for adding reagents along the way; a vacuum pump for removing volatile components under reduced pressure; a belt conveyor for transporting the acid-modified polyolefin resin extruded by the strands; a cutter for cutting the strands; and a header, die, etc., for discharging the acid-modified polyolefin resin.

[0099] In this disclosure, the raw materials may be introduced as powder, pellets, liquid, or mixtures thereof from the inlet or intermediate addition port of a coaxial multi-screw extruder using a feeder, hopper, or side feeder. In this disclosure, the raw materials may be added sequentially or all at once.

[0100] This disclosure provides subject matter in the following aspects: Item 1. A method for producing an acid-modified polyolefin resin using a coaxial multi-screw extruder, comprising: (A) mixing a raw material containing a polyolefin resin and an α,β-unsaturated carboxylic acid and / or its acid anhydride in a raw material mixing section; (B) transporting the mixture obtained in step (A) to a reaction section in a transport section; (C) reacting the transported mixture in the reaction section to obtain a graft polymer of the polyolefin resin and the α,β-unsaturated carboxylic acid and / or its acid anhydride; (D) defoliating the graft polymer in a defoliation section; and (E) cooling the defoliated graft polymer in a adjustment section, wherein the melting point of the acid-modified polyolefin resin is 60 to 160°C, the graft amount of the α,β-unsaturated carboxylic acid and / or its acid anhydride in the acid-modified polyolefin resin is 0.1 to 20% by mass, and the weight-average molecular weight of the acid-modified polyolefin resin is 5,000 to 300,000. A method for producing an acid-modified polyolefin resin using a coaxial multi-screw extruder, wherein the barrel temperature of the raw material mixing section is 15°C or higher and 40°C or lower, and the raw material input amount Q, the screw rotation speed Ns of the reaction section, and the screw diameter D of the reaction section satisfy the following formula (1). 15 ≤ Q / (Ns × D ３) ≤ 40 (1) Item 2. A method for producing an acid-modified polyolefin resin according to Item 1, wherein when the acid-modified polyolefin resin is purified by the purification method described below, the rate of reduction of the graft amount calculated by the following formula (2) is 30% or less. Graft amount reduction rate (%) = [(X - Y) / X] × 100 (2) (In equation (2), X represents the amount of α,β-unsaturated carboxylic acid and / or its acid anhydride grafted in the acid-modified polyolefin resin before purification, as measured using a Fourier transform infrared spectrophotometer, and Y represents the amount of α,β-unsaturated carboxylic acid and / or its acid anhydride grafted in the acid-modified polyolefin resin after purification, as measured using a Fourier transform infrared spectrophotometer.) [Method for purifying acid-modified polyolefin resin] 50 g of freeze-pulverized acid-modified polyolefin resin is weighed onto cylindrical filter paper and placed in a Soxhlet extraction tube. A condenser is attached to a flat-bottom flask containing 1100 mL of acetone, and the resin is extracted by refluxing at the boiling point of acetone for 2 hours in a water bath. After that, the acid-modified polyolefin resin in the cylindrical filter paper is removed and purified by drying under reduced pressure at 100°C for 1 hour. Section 3. The method for producing an acid-modified polyolefin resin according to item 1 or 2, wherein the barrel temperature of the conveying section is 20°C or higher and 60°C or lower. Item 4. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 3, wherein the screw rotation speed Ns of the reaction section is 300 to 1500 rpm. Item 5. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 4, wherein the melting point of the acid-modified polyolefin resin is preferably 62 to 150°C, more preferably 64 to 140°C. Item 6. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 5, wherein the graft amount of the α,β-unsaturated carboxylic acid and / or its acid anhydride in the acid-modified polyolefin resin is preferably 0.4 to 15% by mass, more preferably 0.6 to 10% by mass, even more preferably 0.8 to 5.0% by mass, and still more preferably 1.0 to 4.0% by mass.Item 7. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 6, wherein the weight-average molecular weight of the acid-modified polyolefin resin is preferably 10,000 to 250,000, more preferably 20,000 to 200,000, and even more preferably 30,000 to 150,000. Item 8. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 7, wherein the co-directional multi-screw extruder comprises a raw material mixing section, a conveying section, a reaction section, a devolatilization section, and an adjustment section. Item 9. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 8, wherein the total length of the barrel length of the raw material mixing section, the barrel length of the conveying section, the barrel length of the reaction section, the barrel length of the devolatilization section, and the barrel length of the adjustment section is preferably 70% or more, more preferably 75% or more, even more preferably 80% or more, even more preferably 85% or more, and particularly preferably 90% or more, relative to the overall length of the co-directional multi-screw extruder. Item 10. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 9, wherein steps (A), (B), (C), (D), and (E) are performed in this order. Claim 11. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 10, wherein the raw materials comprise a polyolefin resin, an α,β-unsaturated carboxylic acid and / or its acid anhydride, and a radical generator. Claim 12. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 11, wherein the raw materials comprise a polyolefin resin, an α,β-unsaturated carboxylic acid acid anhydride, and a radical generator. Claim 13. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 12, wherein in step (A), the amount of the α,β-unsaturated carboxylic acid and / or its acid anhydride used is preferably 0.2 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the polyolefin resin. Claim 14. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 13, wherein the barrel temperature of the raw material mixing section is preferably 15°C or more and less than 40°C, more preferably 16°C or more and 39°C or less.Item 15. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 4, wherein the barrel length of the raw material mixing section is preferably 3 to 15% of the total length of the co-directional multi-screw extruder, more preferably 5 to 10% of the total length of the co-directional multi-screw extruder. Item 16. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 15, wherein the polyolefin resin is preferably at least one selected from the group consisting of homopolyethylene, homopolypropylene, and propylene-α-olefin copolymer, and more preferably propylene-α-olefin copolymer. Item 17. The method for producing an acid-modified polyolefin resin according to item 16, wherein the propylene-α-olefin copolymer is preferably propylene-ethylene copolymer, propylene-1-butene copolymer, or propylene-ethylene-1-butene copolymer. Item 18. A method for producing an acid-modified polyolefin resin according to item 16 or 17, wherein the content of the propylene component in the propylene-α-olefin copolymer is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, and particularly preferably 75 mol% or more. Item 19. A method for producing an acid-modified polyolefin resin according to any one of items 1 to 18, wherein the α,β-unsaturated carboxylic acid and / or its acid anhydride is preferably an acid anhydride of an α,β-unsaturated carboxylic acid, more preferably maleic anhydride, itaconic anhydride, citraconic anhydride or aconitic anhydride, and even more preferably maleic anhydride. Item 20. A method for producing an acid-modified polyolefin resin according to any one of items 1 to 19, wherein the barrel temperature of the conveying section is preferably 20°C or more and 60°C or less, more preferably 20°C or more and less than 60°C, even more preferably 25°C or more and less than 60°C, and even more preferably 30°C or more and less than 60°C. Item 21. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 20, wherein the barrel length of the conveying section is preferably 3 to 20% of the total length of the co-directional multi-screw extruder, more preferably 5 to 15% of the total length of the co-directional multi-screw extruder.Item 22. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 21, wherein the barrel temperature of the reaction section is preferably 65°C or higher and 210°C or lower, more preferably 70°C or higher and 180°C or lower, even more preferably 75°C or higher and 150°C or lower, and still more preferably 80°C or higher and less than 120°C. Item 23. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 22, wherein the barrel length of the reaction section is preferably 25 to 55% of the total length of the co-directional multi-screw extruder, more preferably 30 to 50% of the total length of the co-directional multi-screw extruder. Item 24. The method for producing an acid-modified polyolefin resin according to any one of items 1 to 23, wherein the raw material input amount Q is preferably 5 to 500 kg / h, more preferably 10 to 400 kg / h, and even more preferably 15 to 300 kg / h. Item 25. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 24, wherein the screw rotation speed Ns of the reaction section is preferably 300 to 1500 rpm, more preferably 350 to 1300 rpm, and even more preferably 400 to 1100 rpm. Claim 26. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 25, wherein the screw diameter D of the reaction section is preferably 15 mm or more and 100 mm or less, more preferably 20 mm or more and 90 mm or less, and even more preferably 25 mm or more and 80 mm or less. Claim 27. In formula (1), preferably 16 ≤ Q / (Ns × D). ３ ) ≤ 39, more preferably 17 ≤ Q / (Ns × D ３ ) ≤ 38, more preferably 18 ≤ Q / (Ns × D ３A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 26, wherein the pressure is ≤ 37. Claim 28. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 27, wherein the barrel temperature of the devolatilization section is preferably 150°C or more and 200°C or less. Claim 29. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 28, wherein the barrel length of the devolatilization section is preferably 30 to 20% of the total length of the co-directional multi-screw extruder, more preferably 5 to 15% of the total length of the co-directional multi-screw extruder. Claim 30. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 29, wherein the degree of reduced pressure in the devolatilization section is preferably -0.096 MPaG or more and -0.040 MPaG or less, more preferably -0.096 MPaG or more and -0.060 MPaG or less. Claim 31. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 30, wherein the barrel temperature of the adjustment section is preferably 20°C to 210°C, more preferably 50°C to 210°C, even more preferably 75°C to 210°C, and particularly preferably 100°C to 210°C. Claim 32. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 31, wherein the barrel length of the adjustment section is preferably 20 to 40% of the total length of the co-directional multi-screw extruder, more preferably 25 to 35% of the total length of the co-directional multi-screw extruder. Claim 33. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 32, wherein the co-directional multi-screw extruder is preferably a co-directional twin-screw extruder, a co-directional tri-screw extruder, or a co-directional quad-screw extruder, more preferably a co-directional twin-screw extruder. Claim 34. A method for producing an acid-modified polyolefin resin according to any one of claims 1 to 33, wherein the rate of reduction in the amount of graft calculated by formula (2) is more preferably 28% or less, even more preferably 26% or less, even more preferably 24% or less, and particularly preferably 22% or less.

[0101] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to the embodiments described herein.

[0102] First, we will explain the measurement and evaluation methods.

[0103] <Method for Measuring the Melting Point of Acid-Modified Polyolefin Resin> In accordance with JIS K7121-2012, a differential scanning calorimeter (DSC) (Q-2000, manufactured by T.A. Instruments Japan) was used to measure the melting point of 5.0 mg of acid-modified polyolefin resin. The resin was held at -50°C for 5 minutes, then heated from -50°C to 230°C at a rate of 10°C / min to melt it. After that, it was held at 230°C for 2 minutes, then cooled from 230°C to -50°C at a rate of 10°C / min, held at -50°C for 2 minutes, and then heated again from -50°C to 230°C at a rate of 10°C / min. The temperature at which the peak of the melting appeared (°C) was defined as the melting point (Tm) of the acid-modified polyolefin resin.

[0104] <Method for measuring the weight-average molecular weight (Mw) of acid-modified polyolefin resin> The weight-average molecular weight (Mw) of acid-modified polyolefin resin was measured using a gel permeation chromatograph Alliance e2695 manufactured by Waters Ltd. The measurement conditions for gel permeation chromatography (GPC) were as follows. Calibration curves were obtained by dissolving each of the following standard polystyrenes from GL Sciences Co., Ltd.—"Molecular Weight Standard (Lipophilic Polymer) Mw500: Model 2012-2," "Molecular Weight Standard (Lipophilic Polymer) Mw2000: Model 2012-5," "Molecular Weight Standard (Lipophilic Polymer) Mw10000: Model 2012-9," "Molecular Weight Standard (Lipophilic Polymer) Mw20000: Model 2013-1," "Molecular Weight Standard (Lipophilic Polymer) Mw50000: Model 2013-3," and "Molecular Weight Standard (Lipophilic Polymer) Mw200000: Model 2013-7"—at a concentration of 0.5% to prepare tetrahydrofuran (THF) solutions, filtering them, placing them in vials, and then measuring them. [GPC Measurement Conditions] • Standard material: Polystyrene resin (weight-average molecular weight 500, 2000, 50000, 200000) • Acid-modified polyolefin resin concentration: 0.5% by mass • Mobile phase: Tetrahydrofuran (THF) • Column: Shodex KF-806 + KF-803 • Column temperature: 40°C • Flow rate: 1.0 ml / min • Detector: Photodiode array detector (wavelength 254 nm = ultraviolet)

[0105] <Conditions for Chlorination Treatment of Acid-Modified Polyolefin Resin> 280 g of acid-modified polyolefin resin and 2520 g of chloroform were added to an autoclave equipped with a stirrer, and after purging with nitrogen for about 5 minutes, the resin was heated to 110°C to completely dissolve it. Next, 1.4 g of tert-butylperoxy-2-ethylhexanoate was added, and chlorine gas was blown in. After blowing in the predetermined amount of chlorine, the chloroform, which was the reaction solvent, was partially removed by distillation under reduced pressure. This solution was dried under reduced pressure, and the chloroform was completely removed to obtain a chlorinated acid-modified polyolefin resin with a chlorine content of 20%.

[0106] <Method for Measuring Mw of Chlorinated Acid-Modified Polyolefin Resin> The Mw of chlorinated acid-modified polyolefin resin was measured using a gel permeation chromatograph Alliance e2695 manufactured by Waters Japan. The GPC measurement conditions were as follows. The calibration curve was obtained in the same manner as in <Method for Measuring Weight-Average Molecular Weight (Mw) of Acid-Modified Polyolefin Resin> above. [GPC Measurement Conditions] ・Standard substance: Polystyrene resin (weight-average molecular weight 500, 2000, 50000, 200000) ・Concentration of chlorinated acid-modified polyolefin resin: 0.5 mass% ・Mobile phase: Tetrahydrofuran (THF) ・Column: Shodex KF-806 + KF-803 ・Column temperature: 40℃ ・Flow rate: 1.0 ml / min ・Detector: Photodiode array detector (wavelength 254 nm = ultraviolet)

[0107] <Method for calculating the amount of maleic anhydride grafted into acid-modified polyolefin resin> The amount of maleic anhydride grafted into acid-modified polyolefin resin (mass%) was calculated based on the acid value (mgKOH / g-resin) of maleic anhydride in the acid-modified polyolefin resin.

[0108] The acid value (mgKOH / g-resin) of maleic anhydride in the acid-modified polyolefin resin produced in each example and comparative example was calculated using a Fourier transform infrared spectrophotometer (FT-IR) (FT-IR8200PC, manufactured by Shimadzu Corporation) and a calibration curve prepared with maleic anhydride concentrations of 0.1 mass / volume percent, 0.05 mass / volume percent, and 0.0125 mass / volume percent. The coefficient (f) was obtained from this curve and the carbonyl (C=O) bond expansion peak (1780 cm) of maleic anhydride in the maleic anhydride-modified polyolefin resin solution (a mixed solution consisting of maleic anhydride-modified polyolefin resin and chloroform). －１ The absorbance (I) of ) and the molecular weight of maleic anhydride were used to calculate the acid value using the following formula (i): Acid value (mgKOH / g-resin) = [Absorbance (I) × Coefficient (f) × 2 × Molecular weight of potassium hydroxide × 1000 (mg) / Molecular weight of maleic anhydride] ... Formula (i) [In formula (i), the molecular weight of maleic anhydride is 98.06 and the molecular weight of potassium hydroxide is 56.11.]

[0109] Based on the acid value calculated using the above formula (i), the amount of maleic anhydride grafted into the acid-modified polyolefin resin produced in each example and comparative example (mass%) was calculated.

[0110] <Method for Purifying Acid-Modified Polyolefin Resin> The acid-modified polyolefin resins produced in each example and comparative example were freeze-dried and purified by refluxing with acetone for 2 hours using a Soxhlet extractor. Specifically, 50 g of freeze-dried acid-modified polyolefin resin was weighed onto cylindrical filter paper, placed in a Soxhlet extraction tube, and extracted with acetone by refluxing at the boiling point of acetone in a water bath after attaching a condenser to a flat-bottom flask containing 1100 mL of acetone. After that, the acid-modified polyolefin resin powder in the cylindrical filter paper was removed and purified by vacuum drying at 100°C for 1 hour.

[0111] (1) Evaluation of reaction efficiency First, the acid value of maleic anhydride in the acid-modified polyolefin resin immediately after production in each example and comparative example was calculated using the method described above, and the amount of maleic anhydride grafted into the acid-modified polyolefin resin before purification (mass%) was calculated based on the calculated acid value.

[0112] Next, the acid value of maleic anhydride in the acid-modified polyolefin resin purified by the above method was calculated using the same method, and the amount of maleic anhydride grafted into the purified acid-modified polyolefin resin (mass%) was calculated based on the calculated oxidation value.

[0113] The change in the amount of maleic anhydride grafted into the acid-modified polyolefin resin before and after purification (hereinafter also referred to as "change in graft amount before and after purification") was calculated using the following formula (ii): Change in graft amount before and after purification = P - Q ... Formula (ii) P: Amount of maleic anhydride grafted into the acid-modified polyolefin resin before purification Q: Amount of maleic anhydride grafted into the acid-modified polyolefin resin after purification

[0114] The change in the amount of maleic anhydride grafted before and after purification, calculated using the above formula (ii), was evaluated according to the following evaluation criteria. A "○" rating indicates high reaction efficiency, and a "◎" rating indicates excellent reaction efficiency. <Evaluation Criteria> ◎: Change in the amount of maleic anhydride grafted before and after purification is 0.2% by mass or less ○: Change in the amount of maleic anhydride grafted before and after purification is greater than 0.2% by mass and less than or equal to 0.5% by mass △: Change in the amount of maleic anhydride grafted before and after purification is greater than 0.5% by mass and less than or equal to 1.0% by mass ×: Change in the amount of maleic anhydride grafted before and after purification is greater than 1.0% by mass

[0115] (2) Evaluation of operational stability When a co-screw extruder was used to produce maleic anhydride-modified polyolefin resin by feeding in raw materials, passing through the raw material mixing section, conveying section, reaction section, devolatilization section, and adjustment section in that order, then extruding the molten resin in strand form and cutting it into pellet form with a cutter, the operational stability was evaluated according to the following evaluation criteria. Continuous operation possible means that the co-screw extruder could be operated automatically from the time the raw materials were fed in until the molten resin was cut into pellet form with the cutter. Cutting possible means that when the molten resin was extruded in strand form and cut into pellet form with the cutter, the molten resin could be cut without wrapping around the cutter blade.

[0116] If the time for continuous operation and cut-off was 8 hours or more, it was evaluated as good operability with a rating of ◎. If the time for continuous operation and cut-off was 4 hours or more but less than 8 hours, it was evaluated as operable with a rating of ○. If the time for continuous operation and cut-off was less than 4 hours, it was evaluated as difficult to operate with a rating of △. If backflow of raw materials, vent-up in the devolatilization section, etc. occurred and continuous operation was impossible, it was evaluated as impossible to operate with a rating of ×. <Evaluation Criteria> ◎: Continuous operation and cut-off time of 8 hours or more ○: Continuous operation and cut-off time of 4 hours or more but less than 8 hours △: Continuous operation and cut-off time of less than 4 hours ×: Impossible to operate continuously

[0117] The raw materials used in the examples and comparative examples are as follows: <Polyolefin resins> ・A-1: Propylene-ethylene copolymer (propylene content = 98 mol%, ethylene content = 2 mol%, Tm = 130°C) ・A-2: Propylene-1-butene copolymer (propylene content = 80 mol%, 1-butene content = 20 mol%, Tm = 85°C) ・A-3: Propylene-1-butene copolymer (propylene content = 75 mol%, 1-butene content = 25 mol%, Tm = 76°C) ・A-4: Propylene-ethylene-1-butene copolymer (propylene content = 94 mol%, ethylene content = 3.4 mol%, 1-butene content = 2.6 mol%, Tm = 133°C) • A-5: Propylene-1-butene copolymer (propylene content = 85 mol%, 1-butene content = 15 mol%, Tm = 100°C) <α,β-unsaturated carboxylic acid and / or its acid anhydride> • Maleic anhydride (MAH) (manufactured by Tokyo Chemical Industries, Ltd.) <Radical generator> • Di-tert-butyl peroxide (DTBP) (manufactured by NOF Corporation)

[0118] (Example 1) As raw materials, 100 parts by mass of propylene-ethylene copolymer (propylene content = 98 mol%, ethylene content = 2 mol%, Tm = 130°C), 2 parts by mass of maleic anhydride, and 2 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 47 mm and a screw rotation speed Ns = 600 rpm at a raw material input rate Q = 100 kg / h. Q / (Ns × D ３ The ratio was 27. The input raw materials passed through the barrels in the order of raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, and were then discharged in strand form and cut into pellet form with a cutter to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-direction twin-screw extruder was 50 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0119] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 1.6% by mass and a melting point of 124°C. Since the obtained maleic anhydride-modified polyolefin resin did not dissolve in tetrahydrofuran (THF), it was subjected to chlorination treatment, and its weight-average molecular weight (Mw) was measured by GPC, which was 100,000. After acetone extraction (purification), the maleic anhydride graft content was 1.4% by mass. Note that the maleic anhydride graft content (mass%) after purification refers to the maleic anhydride content (mass%) in the maleic anhydride-modified polyolefin resin.

[0120] The details of each barrel in Example 1 are as follows. Hereinafter, "barrel length" refers to the ratio to the total length of the co-screw extruder. The barrel length of the raw material mixing section was 7%, the barrel temperature was 25°C, and the screw configuration was a screw element. The barrel length of the conveying section was 13%, the barrel temperature was 40°C to 60°C, and the screw configuration was a screw element. The barrel length of the reaction section was 33%, the barrel temperature was 80°C to 100°C, the kneading disc occupancy rate in the reaction section was 95%, and the kneading disc configuration was 40% right kneading disc, 10% left kneading disc, and 50% neutral kneading disc. The barrel length of the devolatilization section was 7%, the barrel temperature was 170°C to 200°C, and the screw configuration was a screw element. The degree of vacuum in the devolatilization section was -0.096 MPaG (gauge pressure). The barrel length of the adjustment section was set to 32%, the barrel temperature to be between 190°C and 210°C, and the screw configuration was a screw element.

[0121] (Example 2) As raw materials, 100 parts by mass of propylene-ethylene copolymer (propylene content = 98 mol%, ethylene content = 2 mol%, Tm = 130°C), 2 parts by mass of maleic anhydride, and 2 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 47 mm and a screw rotation speed Ns = 600 rpm at a raw material input rate Q = 100 kg / h. Q / (Ns × D ３The ratio was 27. The input raw materials passed through the barrels in the following order: raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-screw extruder was 50 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0122] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 1.6% by mass and a melting point of 124°C. Since the obtained maleic anhydride-modified polyolefin resin did not dissolve in THF, it was subjected to chlorination treatment, and the weight-average molecular weight (Mw) was measured by the GPC method, which was found to be 100,000. After acetone extraction (purification), the maleic anhydride graft content was 1.4% by mass.

[0123] The details of each barrel in Example 2 were the same as in Example 1, except that the barrel temperature of the raw material mixing section was changed to 38°C.

[0124] (Example 3) As raw materials, 100 parts by mass of propylene-ethylene copolymer (propylene content = 98 mol%, ethylene content = 2 mol%, Tm = 130°C), 2 parts by mass of maleic anhydride, and 2 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 47 mm and a screw rotation speed Ns = 600 rpm at a raw material input rate Q = 100 kg / h. Q / (Ns × D ３ The ratio was 27. The input raw materials passed through the barrels in the following order: raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-screw extruder was 50 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0125] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 1.5% by mass and a melting point of 124°C. Since the obtained maleic anhydride-modified polyolefin resin did not dissolve in THF, it was subjected to chlorination treatment, and the weight-average molecular weight (Mw) was measured by the GPC method, which was found to be 110,000. After acetone extraction (purification), the maleic anhydride graft content was 1.3% by mass.

[0126] The details of each barrel in Example 3 were the same as in Example 1, except that the barrel temperature of the raw material mixing section was changed to 18°C.

[0127] (Example 4) As raw materials, 100 parts by mass of propylene-ethylene copolymer (propylene content = 98 mol%, ethylene content = 2 mol%, Tm = 130°C), 2 parts by mass of maleic anhydride, and 2 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 47 mm and a screw rotation speed Ns = 450 rpm at a raw material input rate Q = 100 kg / h. Q / (Ns × D ３ The ratio was 36. The input raw materials passed through the barrels in the following order: raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-screw extruder was 60 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0128] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 1.4% by mass and a melting point of 124°C. Since the obtained maleic anhydride-modified polyolefin resin did not dissolve in THF, it was subjected to chlorination treatment, and the weight-average molecular weight (Mw) was measured by the GPC method, which was 120,000. After acetone extraction (purification), the maleic anhydride graft content was 1.1% by mass.

[0129] The details of each barrel in Example 4 were the same as those in Example 1.

[0130] (Example 5) As raw materials, 100 parts by mass of propylene-ethylene copolymer (propylene content = 98 mol%, ethylene content = 2 mol%, Tm = 130°C), 2 parts by mass of maleic anhydride, and 2 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 47 mm and a screw rotation speed Ns = 900 rpm at a raw material input rate Q = 100 kg / h. Q / (Ns × D ３ The ratio was 18. The input raw materials passed through the barrels in the following order: raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-screw extruder was 37 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0131] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 1.4% by mass and a melting point of 123°C. Since the obtained maleic anhydride-modified polyolefin resin did not dissolve in THF, it was subjected to chlorination treatment, and the weight-average molecular weight (Mw) was measured by the GPC method, which was found to be 90,000. After acetone extraction (purification), the maleic anhydride graft content was 1.2% by mass.

[0132] The details of each barrel in Example 5 were the same as those in Example 1.

[0133] (Example 6) As raw materials, 100 parts by mass of propylene-1-butene copolymer (propylene content = 80 mol%, 1-butene content = 20 mol%, Tm = 85°C), 2 parts by mass of maleic anhydride, and 2 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 47 mm and a screw rotation speed Ns = 600 rpm at a raw material input rate Q = 100 kg / h. Q / (Ns × D ３The ratio was 27. The input raw materials passed through the barrels in the following order: raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-screw extruder was 50 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0134] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 1.8% by mass, a melting point of 79°C, and a weight-average molecular weight (Mw) of 90,000. After acetone extraction (purification), the maleic anhydride graft content was 1.5% by mass.

[0135] The details of each barrel in Example 6 are as follows: The barrel length of the raw material mixing section was 7%, the barrel temperature was 25°C, and the screw configuration was a screw element. The barrel length of the conveying section was 7%, the barrel temperature was 40°C to 60°C, and the screw configuration was a screw element. The barrel length of the reaction section was 39%, the barrel temperature was 80°C to 100°C, the kneading disc occupancy rate in the reaction section was 95%, and the kneading disc configuration was 55% right kneading disc, 10% left kneading disc, and 35% neutral kneading disc. The barrel length of the devolatilization section was 7%, the barrel temperature was 150°C to 180°C, and the screw configuration was a screw element. The degree of vacuum in the devolatilization section was -0.096 MPaG (gauge pressure). The barrel length of the adjustment section was 32%, the barrel temperature was 100°C to 130°C, and the screw configuration was a screw element.

[0136] (Example 7) As raw materials, 100 parts by mass of propylene-1-butene copolymer (propylene content = 75 mol%, 1-butene content = 25 mol%, Tm = 76°C), 2 parts by mass of maleic anhydride, and 2 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 26 mm and a screw rotation speed Ns = 1100 rpm at a raw material input rate Q = 24 kg / h. Q / (Ns × D ３The ratio was 27. The input raw materials passed through the barrels in the following order: raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-screw extruder was 25 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0137] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 1.8% by mass, a melting point of 69°C, and a weight-average molecular weight (Mw) of 80,000. After acetone extraction (purification), the maleic anhydride graft content was 1.5% by mass.

[0138] The details of each barrel in Example 7 were the same as those in Example 6.

[0139] (Example 8) As raw materials, 100 parts by mass of propylene-ethylene-1-butene copolymer (propylene content = 94 mol%, ethylene content = 3.4 mol%, 1-butene content = 2.6 mol%, Tm = 133°C), 2 parts by mass of maleic anhydride, and 2 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 26 mm and a screw rotation speed Ns = 700 rpm at a raw material input rate Q = 19 kg / h. Q / (Ns × D ３ The ratio was 26. The input raw materials passed through the barrels in the following order: raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-screw extruder was 45 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0140] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 1.3% by mass and a melting point of 124°C. Since the obtained maleic anhydride-modified polyolefin resin did not dissolve in THF, it was subjected to chlorination treatment, and the weight-average molecular weight (Mw) was measured by the GPC method, which was found to be 100,000. After acetone extraction (purification), the maleic anhydride graft content was 1.1% by mass.

[0141] The details of each barrel in Example 8 were the same as those in Example 6.

[0142] (Example 9) As raw materials, 100 parts by mass of propylene-1-butene copolymer (propylene content = 85 mol%, 1-butene content = 15 mol%, Tm = 100°C), 3.5 parts by mass of maleic anhydride, and 2.5 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 26 mm at a raw material input rate Q = 19 kg / h. Q / (Ns × D ３ The ratio was 26. The input raw materials passed through the barrels in the following order: raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-screw extruder was 45 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0143] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 3.0% by mass, a melting point of 94°C, and a weight-average molecular weight (Mw) of 50,000. After acetone extraction (purification), the maleic anhydride graft content was 2.5% by mass.

[0144] The details of each barrel in Example 9 were the same as those in Example 6.

[0145] (Example 10) As raw materials, 100 parts by mass of propylene-ethylene copolymer (propylene content = 98 mol%, ethylene content = 2 mol%, Tm = 130°C), 2 parts by mass of maleic anhydride, and 2 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 69 mm and a screw rotation speed Ns = 450 rpm at a raw material input rate Q = 240 kg / h. Q / (Ns × D ３ The ratio was 27. The input raw materials passed through the barrels in the following order: raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-screw extruder was 40 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0146] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 1.5% by mass, a melting point of 124°C, and a weight-average molecular weight (Mw) of 100,000. After acetone extraction (purification), the maleic anhydride graft content was 1.3% by mass.

[0147] The details of each barrel in Example 10 were the same as those in Example 1.

[0148] (Example 11) As raw materials, 100 parts by mass of propylene-ethylene copolymer (propylene content = 98 mol%, ethylene content = 2 mol%, Tm = 130°C), 2 parts by mass of maleic anhydride, and 2 parts by mass of di-tert-butyl peroxide were fed into a coaxial twin-screw extruder with a screw diameter D = 69 mm and a screw rotation speed Ns = 560 rpm at a raw material input rate Q = 290 kg / h. Q / (Ns × D ３ The ratio was 27. The input raw materials passed through the barrels in the following order: raw material mixing section, conveying section, reaction section, defoliation section, and adjustment section, to obtain maleic anhydride-modified polyolefin resin. The total residence time in the co-screw extruder was 40 seconds. Defoliation was performed in the defoliation section to remove any remaining unreacted material. In the adjustment section, the maleic anhydride-modified polyolefin resin was adjusted to a temperature at which it could be solidified.

[0149] The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft content of 1.5% by mass, a melting point of 124°C, and a weight-average molecular weight (Mw) of 100,000. After acetone extraction (purification), the maleic anhydride graft content was 1.3% by mass.

[0150] The details of each barrel in Example 11 were the same as those in Example 1.

[0151] (Comparative Example 1) A maleic anhydride-modified polyolefin resin was obtained using the same procedure as in Example 1, except that the barrel temperature of the raw material mixing section was changed to 10°C. Q / (Ns×D ３ The ratio was 27. The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft amount of 1.5% by mass and a melting point of 125°C. The obtained maleic anhydride-modified polyolefin resin did not dissolve in tetrahydrofuran (THF), so after chlorination treatment, the weight-average molecular weight (Mw) was measured by the GPC method and was found to be 110,000. After acetone extraction (purification), the maleic anhydride graft amount was 0.9% by mass. Comparative Example 1 was able to produce a maleic anhydride-modified polyolefin resin, but it was inferior in reaction efficiency and operational stability.

[0152] (Comparative Example 2) The procedure was carried out under the same conditions as in Example 1, except that the barrel temperature of the raw material mixing section was changed to 48°C. Q / (Ns×D ３ The ratio was 27. However, in Comparative Example 2, the molten maleic anhydride flowed back into the raw material mixing section and the conveying section, making it impossible to stably obtain maleic anhydride-modified polyolefin resin. Therefore, the reaction efficiency could not be evaluated, and the operational stability was very poor.

[0153] (Comparative Example 3) A maleic anhydride-modified polyolefin resin was obtained by carrying out the experiment under the same conditions as in Example 1, except that the screw rotation speed of the reaction section was changed to Ns = 360 rpm and the residence time for the entire twin-screw extruder in the same direction was set to 86 seconds. Q / (Ns × D ３The ratio was 45. However, in Comparative Example 3, the extrusion load increased, and the output current value of the extruder motor rose to near the upper limit. The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft amount of 1.4% by mass and a melting point of 125°C. Since the obtained maleic anhydride-modified polyolefin resin did not dissolve in tetrahydrofuran (THF), it was subjected to chlorination treatment, and the weight-average molecular weight (Mw) was measured by the GPC method and found to be 120,000. The maleic anhydride graft amount after acetone extraction (purification) was 0.6% by mass. Comparative Example 3 was able to produce a maleic anhydride-modified polyolefin resin, but its reaction efficiency was inferior.

[0154] (Comparative Example 4) The process was carried out under the same conditions as in Example 1, except that the screw rotation speed of the reaction section was changed to Ns = 1150 rpm and the residence time for the entire twin-screw extruder in the same direction was set to 14 seconds, to obtain a maleic anhydride-modified polyolefin resin. Q / (Ns × D ３ The result was 14. The obtained maleic anhydride-modified polyolefin resin had a maleic anhydride graft amount of 1.2% by mass and a melting point of 125°C. The obtained maleic anhydride-modified polyolefin resin did not dissolve in tetrahydrofuran (THF), so after chlorination treatment, the weight-average molecular weight (Mw) was measured by the GPC method and found to be 90,000. After acetone extraction (purification), the maleic anhydride graft amount was 0.6% by mass. Comparative Example 4 was able to produce a maleic anhydride-modified polyolefin resin, but its reaction efficiency was inferior.

[0155] The results for each example and each comparative example are shown in Tables 1 and 2. In Table 1, residence time refers to the residence time for the entire co-screw extruder. In Table 2, KD refers to the kneading disk, KD Right refers to the kneading disk right, KD Left refers to the kneading disk left, and KD Neutral refers to the kneading disk neutral.

[0156]

[0157]

[0158] [Discussion of Results] Examples 4, 6, 7, and 9 demonstrated high reaction efficiency, excellent operational stability, and the ability to produce maleic anhydride-modified polyolefin resin using a co-directional twin-screw extruder without raw material backflow or vent-up. Examples 1-3, 5, and 8 demonstrated excellent reaction efficiency and operational stability, and the ability to produce maleic anhydride-modified polyolefin resin using a co-directional twin-screw extruder without raw material backflow or vent-up. Examples 10 and 11 demonstrated excellent reaction efficiency and operational stability, and the ability to produce maleic anhydride-modified polyolefin resin using a co-directional twin-screw extruder without raw material backflow or vent-up, even when the raw material input amount was increased compared to Examples 1-9.

Claims

1. A method for producing an acid-modified polyolefin resin using a coaxial multi-screw extruder, comprising: (A) a step of mixing raw materials containing a polyolefin resin and an α,β-unsaturated carboxylic acid and / or its acid anhydride in a raw material mixing section; (B) a step of transporting the mixture obtained in step (A) to a reaction section in a transport section; (C) a step of reacting the transported mixture in the reaction section to obtain a graft polymer of the polyolefin resin and the α,β-unsaturated carboxylic acid and / or its acid anhydride; (D) a step of deflorating the graft polymer in a defloration section; and (E) a step of cooling the deflorated graft polymer in a adjustment section, wherein the melting point of the acid-modified polyolefin resin is 60 to 160°C, the graft amount of the α,β-unsaturated carboxylic acid and / or its acid anhydride in the acid-modified polyolefin resin is 0.1 to 20% by mass, and the weight-average molecular weight of the acid-modified polyolefin resin is 5,000 to 300,000. A method for producing an acid-modified polyolefin resin using a coaxial multi-screw extruder, wherein the barrel temperature of the raw material mixing section is 15°C or higher and 40°C or lower, and the raw material input amount Q, the screw rotation speed Ns of the reaction section, and the screw diameter D of the reaction section satisfy the following formula (1). 15 ≤ Q / (Ns × D ３ ) ≤ 40 (1) 2. A method for producing an acid-modified polyolefin resin according to claim 1, wherein when the acid-modified polyolefin resin is purified by the purification method described below, the rate of reduction in the amount of graft calculated by the following formula (2) is 30% or less. Rate of reduction in amount of graft (%) = [(X - Y) / X] × 100 (2) (In formula (2), X represents the amount of graft of α,β-unsaturated carboxylic acid and / or its acid anhydride in the acid-modified polyolefin resin before purification, as measured using a Fourier transform infrared spectrophotometer, and Y represents the amount of graft of α,β-unsaturated carboxylic acid and / or its acid anhydride in the acid-modified polyolefin resin after purification, as measured using a Fourier transform infrared spectrophotometer.) [Method for purifying acid-modified polyolefin resin] 50 g of freeze-pulverized acid-modified polyolefin resin is weighed onto cylindrical filter paper and placed in a Soxhlet extraction tube. A condenser is attached to a flat-bottom flask containing 1100 mL of acetone, and acetone extraction is performed by refluxing at the boiling point of acetone for 2 hours in a water bath. Subsequently, the acid-modified polyolefin resin is removed from the cylindrical filter paper and purified by vacuum drying at 100°C for 1 hour.

3. The method for producing an acid-modified polyolefin resin according to claim 1 or 2, wherein the barrel temperature of the conveying section is 20°C or higher and 60°C or lower.

4. The method for producing an acid-modified polyolefin resin according to claim 1 or 2, wherein the screw rotation speed Ns of the reaction section is 300 to 1500 rpm.

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