Polymer composition and method for producing polymer composition, and aqueous dispersion composition

Abstract

A polymer composition containing a modified polypropylene modified by at least one selected from the group consisting of unsaturated carboxylic acids and derivatives thereof, wherein the difference (X1-X2) between the content of unsaturated carboxylic acid and / or derivative thereof in the polymer composition before acetone extraction (X1) and the content of unsaturated carboxylic acid and / or derivative thereof in the polymer composition after acetone extraction (X2) is from 0.01 mass% to 0.5 mass%, the content of unsaturated carboxylic acid and / or derivative thereof in the polymer composition after acetone extraction (X2) is from 0.7 mass% to 1.8 mass%, and the MFR, measured at 180°C with a load of 2.16 kg and a 1 mm orifice according to JIS K7210, is from 1 g / 10 min to 40 g / 10 min.

Description

Polymer composition, method for producing polymer composition, and aqueous dispersion composition

[0001] The present invention relates to a polymer composition that enables the production of an adhesive having excellent adhesion and heat resistance, and a method for producing the same. The present invention also relates to an adhesive containing the polymer composition, a polymer composition for aqueous dispersions comprising the polymer composition, and an aqueous dispersion composition containing the polymer composition.

[0002] In the fields of building materials and automobiles, components are used in which adherends with low polarity, such as polypropylene or ABS, are bonded to adherends with metals or highly polarity using adhesives. In light of recent environmental considerations, solvent-free adhesives that do not use organic solvents are required for the adhesives used here.

[0003] Known solvent-free adhesives capable of adhering to these adherends are those made of aqueous dispersion compositions containing acid-modified polyolefins (Patent Documents 1 and 2).

[0004] JP 2015-117382 A JP 2015-163688 A

[0005] Adhesives for building materials and automotive applications require adhesives with improved adhesion and heat resistance, but conventional adhesives containing acid-modified polyolefins have room for improvement in terms of achieving both adhesion and heat resistance.

[0006] An object of the present invention is to provide a polymer composition that enables the production of an adhesive having excellent adhesion and heat resistance, and a method for producing the same. Another object of the present invention is to provide an adhesive containing the polymer composition, a polymer composition for aqueous dispersions comprising the polymer composition, and an aqueous dispersion composition containing the polymer composition.

[0007] The present inventors have found that, in a polymer composition containing an unsaturated carboxylic acid-modified polypropylene and an unsaturated carboxylic acid, a polymer composition capable of being used as an adhesive having excellent adhesiveness and heat resistance can be obtained by adjusting the modification rate of the unsaturated carboxylic acid-modified polypropylene, the content of the unsaturated carboxylic acid, and the MFR to specific ranges. The present invention has the following characteristics.

[0008] [1] A polymer composition containing a modified polypropylene modified with at least one selected from the group consisting of unsaturated carboxylic acids and derivatives thereof, wherein the difference (X1-X2) between the mass percentage X1 (mass%) defined below and the mass percentage X2 (mass%) defined below is 0.01 mass% or more and 0.5 mass% or less, the mass percentage X2 (mass%) is 0.7 mass% or more and 1.8 mass% or less, and the MFR of the polymer composition measured in accordance with JIS K7210 under conditions of 180°C, a load of 2.16 kg, and a 1 mm orifice is 1 g / 10 min or more and 40 g / 10 min or less. Mass percentage X1 (mass%): The polymer composition is press-molded into a circular sheet having a thickness of 100 μm and a diameter of 20 mm under conditions of 200°C, 5 MPa, and 3 minutes, and the circular sheet is used as a measurement sample. The MFR of the polymer composition is 1 g / 10 min or more and 40 g / 10 min or less by infrared absorption spectroscopy. －１ The mass ratio (mass %) of the total mass of the unsaturated carboxylic acid and / or derivative thereof graft-polymerized onto polypropylene in the measurement sample and the mass of the unsaturated carboxylic acid and / or derivative thereof present as a simple substance in the measurement sample, calculated using a calibration curve from the measured carbonyl characteristic absorption of the unsaturated carboxylic acid and / or derivative thereof, relative to the measurement sample. Mass ratio X2 (mass %): The polymer composition is press-molded into a circular sheet having a thickness of 100 μm and a diameter of 20 mm under conditions of 200° C., 5 MPa, and 3 minutes. The circular sheet is placed in a Soxhlet extractor, refluxed with acetone at 80° C. for 1 hour, and then dried at 80° C. for 2 hours. This circular sheet is used as a measurement sample for infrared absorption spectrum, and is measured by infrared absorption spectroscopy in the range of 1900 to 1600 cm. －１ The mass ratio (mass%) of the unsaturated carboxylic acid and / or derivative thereof graft-polymerized to polypropylene in the measurement sample relative to the measurement sample is calculated using a calibration curve from the measured carbonyl characteristic absorption of

[0009] [2] The polymer composition according to [1], which has an MFR of 5 g / 10 min or more and 40 g / 10 min or less, measured according to JIS K7210 under conditions of 180°C, a load of 2.16 kg, and a 1 mm orifice.

[0010] [3] The polymer composition according to [1] or [2], which is a polymer composition for aqueous dispersion.

[0011] [4] A method for producing a polymer composition according to any one of [1] to [3], comprising a step of reacting a raw material polypropylene containing a polypropylene (a) having a flexural modulus of 100 MPa or more and 2000 MPa or less with an unsaturated carboxylic acid and / or a derivative thereof (b) in the presence of a peroxyester (c1) and a dialkyl peroxide (c2).

[0012] [5] The method for producing a polymer composition according to [4], wherein the peroxyester (c1) is t-butylperoxyisopropyl carbonate.

[0013] [6] The method for producing a polymer composition according to [4] or [5], wherein the dialkyl peroxide (c2) is di-t-butyl peroxide.

[0014] [7] The method for producing a polymer composition according to any one of [4] to [6], wherein the raw material polypropylene further contains polypropylene (d) having a flexural modulus of less than 100 MPa or a viscosity at 190°C of 100 cP or more and 3000 cP or less.

[0015] [8] The method for producing a polymer composition according to any one of [4] to [7], wherein a content of the polypropylene (a) relative to 100% by mass of the raw material polypropylene is 50% by mass or more and 100% by mass or less.

[0016] [9] The method for producing a polymer composition according to [7] or [8], wherein the content of the polypropylene (d) is 1% by mass or more and 50% by mass or less relative to 100% by mass of the raw material polypropylene.

[0017]

[10] An adhesive comprising the polymer composition according to any one of [1] to [3].

[0018]

[11] An aqueous dispersion composition comprising the polymer composition according to any one of [1] to [3], a surfactant, and water.

[0019] According to the polymer composition of the present invention and the aqueous dispersion composition containing this polymer composition, an adhesive having excellent adhesiveness and heat resistance can be provided.

[0020] The following describes in detail the embodiments of the present invention. The present invention is not limited to the following description, and can be implemented by any modifications within the scope of the gist of the present invention. In this specification, when an expression using "~" is used with a numerical value or physical property value before and after it, the value before and after it is used as including the values ​​before and after it.

[0021] Hereinafter, the monomer units contained in the copolymer may be simply referred to as "units." For example, a monomer unit based on propylene may be referred to as a "propylene unit," and a monomer unit based on ethylene and a monomer unit based on an α-olefin may be referred to as an "ethylene unit" and an "α-olefin unit," respectively.

[0022] In the present invention, the MFR (melt flow rate) of the polymer composition is measured in accordance with JIS K7210 under conditions of 180°C, a load of 2.16 kg, and a 1 mm orifice. The MFR (melt flow rate) of polypropylene is measured in accordance with JIS K7210 under conditions of 230°C, a load of 2.16 kg, and a 2 mm orifice.

[0023] In the present invention, the flexural modulus of the polymer composition and polypropylene is a value measured in accordance with JIS K 7171.

[0024] The viscosity of polypropylene at 190°C is a viscosity measured at 190°C by a method in accordance with JIS K 2283. The density of polypropylene is a value measured in accordance with JIS K 7112.

[0025] [Polymer composition] The polymer composition of the present invention is a polymer composition containing a modified polypropylene modified with at least one selected from the group consisting of unsaturated carboxylic acids and derivatives thereof (hereinafter, sometimes referred to as the "modified polypropylene of the present invention"), characterized in that the difference (X1-X2) between the mass proportion X1 (mass%) defined below and the mass proportion X2 (mass%) defined below is 0.01 mass% or more and 0.5 mass% or less, the mass proportion X2 (mass%) below is 0.7 mass% or more and 1.8 mass% or less, and the MFR of the polymer composition measured in accordance with JIS K7210 under conditions of 180°C, a load of 2.16 kg, and a 1 mm orifice is 1 g / 10 min or more and 40 g / 10 min or less. Mass proportion X1 (mass%): The polymer composition is press-molded into a circular sheet having a thickness of 100 μm and a diameter of 20 mm under conditions of 200°C, 5 MPa, and 3 minutes, and the circular sheet is used as a measurement sample, and the MFR is measured at 1900 to 1600 cm by infrared absorption spectroscopy. －１ The mass ratio (mass %) of the total mass of the unsaturated carboxylic acid and / or derivative thereof graft-polymerized onto polypropylene in the measurement sample and the unsaturated carboxylic acid and / or derivative thereof present as a simple substance in the measurement sample, calculated using a calibration curve from the measured carbonyl characteristic absorption of the unsaturated carboxylic acid and / or derivative thereof, relative to the measurement sample. Mass ratio X2 (mass %): The polymer composition is press-molded into a circular sheet having a thickness of 100 μm and a diameter of 20 mm under conditions of 200° C., 5 MPa, and 3 minutes. The circular sheet is placed in a Soxhlet extractor, refluxed with acetone at 80° C. for 1 hour, and then dried at 80° C. for 2 hours. This circular sheet is used as a measurement sample for infrared absorption spectrum, and is measured by infrared absorption spectroscopy in the range of 1900 to 1600 cm. －１ The mass ratio (mass%) of the unsaturated carboxylic acid and / or derivative thereof graft-polymerized to polypropylene in the measurement sample relative to the measurement sample is calculated using a calibration curve from the measured carbonyl characteristic absorption of

[0026] Hereinafter, the mass percentage X1 (mass%) may be referred to as "the content (X1) of unsaturated carboxylic acid and / or derivatives thereof in the polymer composition before acetone extraction," and the mass percentage X2 (mass%) may be referred to as "the content (X2) of unsaturated carboxylic acid and / or derivatives thereof in the polymer composition after acetone extraction."

[0027] The polymer composition of the present invention contains a modified polypropylene modified with an unsaturated carboxylic acid and / or a derivative thereof, and, as will be described later, an unsaturated carboxylic acid and / or a derivative thereof that exists as a simple substance without being graft-polymerized onto the modified polypropylene after the modification treatment of the raw material polypropylene. Therefore, the polymer composition is called a "polymer composition," but is also industrially called a "modified polypropylene."

[0028] The polymer composition of the present invention is preferably produced according to the method for producing a polymer composition of the present invention by reacting a raw material polypropylene containing a polypropylene (a) having a flexural modulus of 100 MPa or more and 2000 MPa or less with an unsaturated carboxylic acid and / or a derivative thereof (b) in the presence of a peroxyester (c1) and a dialkyl peroxide (c2).

[0029] The polymer composition of the present invention is useful as an adhesive component of an aqueous dispersion composition used as a water-based adhesive.

[0030] [Mass Proportion X1 (mass %) and Mass Proportion X2 (mass %) of Polymer Composition] <Mass Proportion X1 (mass %)> The mass proportion X1 (mass %), which is the content (X1) of unsaturated carboxylic acid and / or derivative thereof in the polymer composition before acetone extraction when the polymer composition is taken as 100 mass %, is a value measured as follows. The polymer composition is press-molded into a circular sheet having a thickness of 100 μm and a diameter of 20 mm under conditions of 200° C., 5 MPa, and 3 minutes to obtain a circular sheet. This circular sheet is used as a sample for measuring infrared absorption spectrum, and the content of carboxylic acid and / or derivative thereof is determined using infrared absorption spectroscopy from absorption specific to carboxylic acid and / or derivative thereof. Specifically, the mass proportion X1 (mass %) is measured using a method for measuring the content of carboxylic acid and / or derivative thereof from absorption specific to carboxylic acid and / or derivative thereof in a range of 1900 to 1600 cm －１The carbonyl characteristic absorption (C═O stretching vibration band) is measured. The value thus obtained is the content (X1) of the unsaturated carboxylic acid and / or its derivative in the polymer composition before acetone extraction, i.e., the mass proportion X1 (mass%), when the polymer composition is taken as 100 mass%.

[0031] <Mass Proportion X2 (mass %)> The mass proportion X2 (mass %), which is the content (X2) of the unsaturated carboxylic acid and / or its derivative in the polymer composition after acetone extraction when the polymer composition is taken as 100 mass %, is a value measured as follows. The polymer composition is press-molded into a circular sheet having a thickness of 100 μm and a diameter of 20 mm at 200°C, 5 MPa, and 3 minutes to obtain a circular sheet. This circular sheet is placed in a Soxhlet extractor and subjected to acetone reflux at 80°C for 1 hour. The acetone extraction is performed for the purpose of removing the unsaturated carboxylic acid and / or its derivative that is not graft-polymerized to polypropylene and exists as a reaction residue in the polymer composition. The circular sheet is then dried at 80°C for 2 hours using a heated dryer. The dried circular sheet is used as a sample for infrared absorption spectroscopy, and the content of the carboxylic acid and / or its derivative is determined from the absorption characteristic of the carboxylic acid and / or its derivative using infrared absorption spectroscopy. Specifically, the content of the carboxylic acid and / or its derivative is determined from the absorption characteristic of the carboxylic acid and / or its derivative in the range of 1900 to 1600 cm －１ The carbonyl characteristic absorption (C═O stretching vibration band) is measured to determine the mass proportion X2 (mass%), which is the content (X2) of the unsaturated carboxylic acid and / or its derivative in the polymer composition after acetone extraction, when the polymer composition is taken as 100 mass%.

[0032] The mass percentage X1 (mass%) means the content of the unsaturated carboxylic acid and / or its derivative graft-polymerized onto the modified polypropylene contained in the polymer composition, and the content of the unsaturated carboxylic acid and / or its derivative present as a simple substance in the polymer composition as a reaction residue. On the other hand, the mass percentage X2 (mass%) means the content of the unsaturated carboxylic acid and / or its derivative present as a simple substance in the polymer composition as a reaction residue. Therefore, the difference (X1-X2) between the mass percentage X1 (mass%) of the polymer composition (100 mass%) and the mass percentage X2 (mass%) means the content of the unsaturated carboxylic acid and / or its derivative present as a simple substance in the polymer composition as a reaction residue.

[0033] The mass ratio X2 (mass%), i.e., the content of the unsaturated carboxylic acid and / or its derivative graft-polymerized to the modified polypropylene contained in the polymer composition, can also be confirmed by the following NMR spectrum measurement. 25 mg of a sample of the methyl esterified polymer composition is weighed into an NMR sample tube with an outer diameter of 5 mm, and 0.52 mL of deuterated orthodichlorobenzene (ODCB-d4) is added and dissolved at 130°C. Using a Bruker AVANCE NEO 600 spectrometer, １ The H-NMR spectrum was measured to determine the methyl ester of the acid-modified polyolefin in the polymer composition. １ Furthermore, the acid-modified polyolefin in the polymer composition before methyl esterification was determined by H-NMR. １ From H-NMR, it was found that the methyl ester １ The area of ​​the peak derived from impurities that overlaps with the peak position of the methyl esterified product in H-NMR is identified. The peak area of ​​the methyl esterified product is determined by subtracting the peak area derived from the impurity from the peak area at the peak position of the methyl esterified product, and X2, which is the content of unsaturated carboxylic acid and / or derivatives thereof graft-polymerized onto the modified polypropylene contained in the polymer composition, can be calculated from the ratio between the mass of the acid-modified group derived based on this and the mass of the acid-modified polyolefin in the polymer composition before methyl esterification.

[0034] <Mass Proportion X1 (% by mass)> In the polymer composition of the present invention, the content (X1) of the unsaturated carboxylic acid and / or its derivative in the polymer composition before acetone extraction is preferably 0.7% by mass or more and 2.3% by mass or less, where the polymer composition is taken as 100% by mass. From the viewpoint of heat resistance, the upper limit of the mass proportion X1 (% by mass) is more preferably 2.2% by mass or less, and even more preferably 2.1% by mass or less.

[0035] <Mass Percentage X2 (% by mass)> In the polymer composition of the present invention, the mass percentage X2 (% by mass), which is the content (X2) of unsaturated carboxylic acid and / or derivative thereof in the polymer composition after acetone extraction, when the polymer composition is taken as 100% by mass, is 0.7% by mass or more and 1.8% by mass or less. When the lower limit of the mass percentage X2 (% by mass) is 0.7% by mass or more, the content of the unsaturated carboxylic acid and / or derivative thereof graft-polymerized to the modified polypropylene is high, thereby effectively exhibiting adhesion to the adherend and improving dispersibility in aqueous solvents. From this perspective, the lower limit of the mass percentage X2 (% by mass) is preferably 0.8% by mass or more, more preferably 0.9% by mass or more. On the other hand, when the upper limit of the mass percentage X2 (% by mass) is 1.8% by mass or less, excessive reaction with the adherend can be suppressed. From this perspective, the upper limit of the mass percentage X2 (% by mass) is preferably 1.7% by mass or less, more preferably 1.6% by mass or less.

[0036] The mass proportion X2 (mass %) can be controlled by the amount of unsaturated carboxylic acid and / or its derivative (b) added during the modification treatment of the raw material polypropylene described below, and the type and amount of the radical generator used.

[0037] <Difference (X1-X2) between Mass Proportion X1 (% by mass) and Mass Proportion X2 (% by mass)> In the polymer composition of the present invention, the difference (X1-X2) between the mass proportion X1 (% by mass), which is the content (X1) of unsaturated carboxylic acid and / or derivative thereof in the polymer composition before acetone extraction, and the mass proportion X2 (% by mass), which is the content (X2) of unsaturated carboxylic acid and / or derivative thereof in the polymer composition after acetone extraction, when the polymer composition is taken as 100% by mass (hereinafter, sometimes referred to as the "content of unsaturated carboxylic acid and / or derivative thereof present as a simple substance") is 0.01% by mass or more and 0.5% by mass or less. By setting the upper limit of the content (X1-X2) of unsaturated carboxylic acid and / or derivative thereof present as a simple substance to 0.5% by mass or less, adhesion inhibition due to unsaturated carboxylic acid and / or derivative thereof present as a simple substance can be suppressed and odor can be reduced. From this viewpoint, the upper limit of the content (X1-X2) of the unsaturated carboxylic acid and / or its derivative present as a simple substance is usually 0.5% by mass or less, and preferably 0.4% by mass or less. On the other hand, the lower limit of the content (X1-X2) of the unsaturated carboxylic acid and / or its derivative present as a simple substance is not particularly limited, but is usually 0.01% by mass or more.

[0038] The content (X1-X2) of the unsaturated carboxylic acid and / or derivative thereof (b) present as a simple substance can be controlled by the amount of the unsaturated carboxylic acid and / or derivative thereof (b) added during the modification treatment of the raw material polypropylene described below, and the type and amount of the radical generator used.

[0039] [MFR] The polymer composition of the present invention has an MFR of 1 g / 10 min or more and 40 g / 10 min or less, measured according to JIS K7210 under conditions of 180°C, a load of 2.16 kg, and a 1 mm orifice. When the lower limit of MFR is 1 g / 10 min or more, the fluidity required as an adhesive can be ensured. From this perspective, the lower limit of MFR measured under the above measurement conditions of the polymer composition of the present invention is preferably 5 g / 10 min or more. On the other hand, when the upper limit of MFR measured under the above measurement conditions of the polymer composition is 40 g / 10 min or less, the heat resistance required as an adhesive can be ensured. From this perspective, the upper limit of MFR measured under the above measurement conditions of the polymer composition of the present invention is preferably 35 g / 10 min or less.

[0040] [Modified Polypropylene] The modified polypropylene of the present invention is a modified polypropylene obtained by modifying polypropylene with at least one selected from the group consisting of unsaturated carboxylic acids and derivatives thereof. The modified polypropylene of the present invention is produced by modifying a raw material polypropylene and an unsaturated carboxylic acid and / or a derivative thereof (b) described below in the presence of a radical generator.

[0041] The polypropylene to be modified (referred to as "raw polypropylene" in the present invention) is not particularly limited, and a propylene homopolymer or a copolymer of propylene and another monomer can be used. Examples of other monomers that can constitute the copolymer include α-olefins having 3 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 1-hexene, 4-methyl-1-hexene, 1-heptene, 1-octene, 1-decene, and 1-octadecene. These other monomers may be used alone or in any combination of two or more.

[0042] Specific examples of polypropylene to be modified include propylene-based copolymers such as propylene-ethylene random copolymers, propylene-butene random copolymers, propylene-ethylene-hexene random copolymers, propylene-ethylene-octene random copolymers, propylene-butene-hexene random copolymers, propylene-butene-octene random copolymers, propylene-hexene-octene random copolymers, and propylene-ethylene block copolymers.

[0043] In particular, from the viewpoint of achieving both heat resistance and adhesiveness, the raw polypropylene preferably contains polypropylene having a flexural modulus of 100 MPa or more and 2000 MPa or less (hereinafter sometimes referred to as polypropylene (a)), and more preferably contains polypropylene (a) and polypropylene having a flexural modulus of less than 100 MPa (hereinafter sometimes referred to as polypropylene (d)). It is even more preferable that the polypropylene (d) contains one having a flexural modulus of 1 MPa or more and less than 100 MPa.

[0044] The polypropylene (a) and the polypropylene (d) may be of the same type or different types, provided that they each have a flexural modulus within the above range.

[0045] <Polypropylene (a) with a flexural modulus of 100 MPa or more and 2000 MPa or less> (Flexural modulus) The flexural modulus of polypropylene (a) is 100 MPa or more and 2000 MPa or less. When the lower limit of the flexural modulus of polypropylene (a) is 100 MPa or more, the mechanical strength and heat resistance of the resulting adhesive can be improved. From this perspective, the lower limit of the flexural modulus of polypropylene (a) is preferably 200 MPa or more, more preferably 300 MPa or more. On the other hand, when the upper limit of the flexural modulus of polypropylene (a) is 2000 MPa or less, the impact resistance can be improved. From this perspective, the upper limit of the flexural modulus of polypropylene (a) is preferably 1800 MPa or less, more preferably 1500 MPa or less.

[0046] The flexural modulus of polypropylene (a) can be controlled by the type and content of other monomers than propylene in the propylene copolymer. For example, in the case of a propylene-ethylene copolymer, the flexural modulus tends to decrease as the content of ethylene units increases.

[0047] (MFR) The MFR of polypropylene (a), measured according to JIS K7210 at 230°C under a load of 2.16 kg, is preferably 10 g / 10 min or more and 50 g / 10 min or less. When the lower limit of the MFR of polypropylene (a) is 10 g / 10 min or more, the fluidity of the modified polypropylene of the present invention can be maintained within a desired range. From this perspective, the lower limit of the MFR of polypropylene (a) is more preferably 20 g / 10 min or more. On the other hand, when the upper limit of the MFR of polypropylene (a) measured under the above measurement conditions is 50 g / 10 min or less, the mechanical strength required as an adhesive can be maintained. From this perspective, the upper limit of the MFR of polypropylene (a) is more preferably 40 g / 10 min or less.

[0048] When two or more types of polypropylene (a) are used, even if some of the polypropylenes (a) have an MFR outside the above range, it is acceptable as long as the overall MFR is within the above range.

[0049] (Density) The density of polypropylene (a) is 0.890 g / cm ３ 0.910g / cm or more ３ The lower limit of the density of the polypropylene (a) is preferably 0.890 g / cm or less. ３ From this viewpoint, the lower limit of the density of the polypropylene (a) is 0.895 g / cm 3 or more, so that the mechanical strength can be maintained. ３ On the other hand, the upper limit of the density of polypropylene (a) is 0.910 g / cm ３ From this viewpoint, the upper limit of the density of the polypropylene (a) is 0.905 g / cm or less, which can provide appropriate flexibility. ３ The following is more preferred:

[0050] When two or more types of polypropylene (a) are used, even if some of the polypropylenes (a) have densities outside the above range, it is acceptable as long as the density of the entire polypropylene (a) is within the above range.

[0051] (Commercially Available Polypropylene (a)) As the polypropylene (a), a commercially available product may be used. An example of the commercially available polypropylene (a) is "WINTEC (registered trademark)" manufactured by Japan Polypropylene Corporation.

[0052] <Polypropylene (d) having a flexural modulus of less than 100 MPa or a viscosity at 190°C of 100 cP to 3000 cP> (Flexural modulus / viscosity) The flexural modulus of polypropylene (d) is less than 100 MPa or a viscosity at 190°C of 100 cP to 3000 cP. The lower limit of the flexural modulus of polypropylene (d) is not particularly limited, but having a flexural modulus of 1 MPa or more tends to easily impart flexibility suitable for the adhesive. From this perspective, the lower limit of the flexural modulus of polypropylene (d) is more preferably 5 MPa or more. On the other hand, having an upper limit of the flexural modulus of polypropylene (d) less than 100 MPa can impart a minimum level of flexibility to the adhesive when used in combination with polypropylene (a). From this perspective, the upper limit of the flexural modulus of polypropylene (d) is preferably 90 MPa or less, more preferably 80 MPa or less. Even if the polypropylene (d) is soft and the flexural modulus cannot be measured, it can be used as the polypropylene (d) as long as the viscosity at 190°C is 100 cP or more and 3000 cP or less.

[0053] The flexural modulus and viscosity of polypropylene (d) can be controlled by the type and content of monomers other than propylene in the propylene copolymer, similar to the flexural modulus of polypropylene (a).

[0054] (MFR) The MFR of polypropylene (d), measured according to JIS K7210 at 230°C under a load of 2.16 kg, is preferably 1 g / 10 min or more and 30 g / 10 min or less. If the lower limit of the MFR of polypropylene (d) is 1 g / 10 min or more, the fluidity required for the adhesive can be ensured. From this perspective, the lower limit of the MFR of polypropylene (d) is more preferably 2 g / 10 min or more. On the other hand, the upper limit of the MFR of polypropylene (d) measured under the above measurement conditions is not particularly limited, but if it is 30 g / 10 min or less, heat resistance can be maintained. From this perspective, the upper limit of the MFR of polypropylene (d) is more preferably 20 g / 10 min or less.

[0055] When two or more types of polypropylene (d) are used, even if some of the polypropylenes (d) have an MFR outside the above range, it is acceptable as long as the overall MFR is within the above range.

[0056] (Density) The density of polypropylene (d) is 0.855 g / cm ３ 0.885g / cm or more ３ The lower limit of the density of the polypropylene (d) is preferably 0.855 g / cm or less. ３ From this viewpoint, the lower limit of the density of the polypropylene (d) is 0.860 g / cm ３ On the other hand, the upper limit of the density of polypropylene (d) is 0.885 g / cm ３ From this viewpoint, the upper limit of the density of polypropylene (d) is 0.880 g / cm ３ The following is more preferred:

[0057] When two or more types of polypropylene (d) are used, even if some of the polypropylenes (d) have densities outside the above range, it is acceptable as long as the density of the entire polypropylene (d) is within the above range.

[0058] (Commercially Available Polypropylene (d)) As the polypropylene (d), a commercially available product may be used. Examples of commercially available polypropylene (d) include "Vistamaxx (registered trademark)" manufactured by EXXON Mobil.

[0059] <Contents of Polypropylene (a) and Polypropylene (d)> The raw material polypropylene of the modified polypropylene may consist of only polypropylene (a), or may contain polypropylene (a) and polypropylene (d).

[0060] The content of polypropylene (a) relative to 100% by mass of raw material polypropylene is preferably 50% by mass or more and 100% by mass or less, preferably 50% by mass or more and 99% by mass or less, more preferably 55% by mass or more and 95% by mass or less, and even more preferably 60% by mass or more and 90% by mass or less. If the content of polypropylene (a) in the raw material polypropylene is not more than the above lower limit, the mechanical strength and heat resistance of the resulting adhesive can be made good. On the other hand, if the content of polypropylene (a) is not more than the above upper limit, the content of polypropylene (d) can be ensured, and flexibility can be imparted to the resulting adhesive.

[0061] When the raw polypropylene contains polypropylene (a) and polypropylene (d), the content of polypropylene (d) relative to 100% by mass of the raw polypropylene is preferably 1% by mass or more and 50% by mass or less, preferably 5% by mass or more and 45% by mass or less, and more preferably 10% by mass or more and 40% by mass or less. If the content of polypropylene (d) in the raw polypropylene is equal to or greater than the lower limit, the resulting adhesive can be imparted with good flexibility. On the other hand, if the content of polypropylene (d) is equal to or less than the upper limit, the content of polypropylene (a) can be ensured, and the resulting adhesive can have good mechanical strength and heat resistance.

[0062] <Unsaturated Carboxylic Acid and / or Derivative Thereof (b)> The unsaturated carboxylic acid used to modify the raw material polypropylene is preferably an α,β-ethylenically unsaturated carboxylic acid, such as acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, tetrahydrofumaric acid, itaconic acid, citraconic acid, crotonic acid, or isocrotonic acid. Examples of derivatives of unsaturated carboxylic acids include acid anhydrides and carboxylic acid esters of these unsaturated carboxylic acids. The derivatives of unsaturated carboxylic acids may also be derivatives such as acid halides, amides, and imides of these unsaturated carboxylic acids. Of these derivatives, acid anhydrides are preferred. The unsaturated carboxylic acid and / or derivative thereof (b) may be used alone or in combination of two or more. Of these, maleic acid and / or its anhydride are particularly preferred as the unsaturated carboxylic acid and / or derivative thereof (b).

[0063] As a modifier for the raw material polypropylene, so-called vinylsilanes such as vinyltrimethoxysilane can also be used in combination with the unsaturated carboxylic acid and / or its derivative (b).

[0064] The amount of unsaturated carboxylic acid and / or derivative thereof (b) used, i.e., the amount blended into the raw material mixture subjected to the modification treatment, is typically 0.7 parts by mass or more, preferably 0.9 parts by mass or more, more preferably 1.1 parts by mass or more, and typically 2.5 parts by mass or less, preferably 2.3 parts by mass or less, more preferably 2.1 parts by mass or less, per 100 parts by mass of raw material polypropylene. By blending the unsaturated carboxylic acid and / or derivative thereof (b) in an amount equal to or greater than the above-mentioned lower limit, sufficient modification is easily achieved. By blending the unsaturated carboxylic acid and / or derivative thereof (b) in an amount equal to or less than the above-mentioned upper limit, it is economical and can reduce the content of unsaturated carboxylic acid and / or derivative thereof (b) that did not contribute to the modification in the resulting polymer composition, i.e., the content (X1-X2) of unsaturated carboxylic acid and / or derivative thereof present as a simple substance.

[0065] <Radical Generator> The modification treatment of the raw material polypropylene with the unsaturated carboxylic acid and / or its derivative (d) is preferably carried out in the presence of a radical generator. The radical generator is used to carry out a radical reaction when the raw material polypropylene is modified with the unsaturated carboxylic acid and / or its derivative (d).

[0066] Examples of the radical generator include peroxyesters (c1), dialkyl peroxides (c2), diacyl peroxides, hydroperoxides, ketone peroxides, etc. Among these, it is preferable to use the peroxyesters (c1) and the dialkyl peroxides (c2) in combination.

[0067] The peroxyesters (c1) are used to enhance the reactivity of the raw polypropylene with the unsaturated carboxylic acid and / or its derivative (d), and the dialkyl peroxides (c2) are used to increase the MFR of the resulting modified polypropylene, i.e., the polymer composition.

[0068] The peroxy ester (c1) is preferably t-butylperoxyisopropyl carbonate, and the dialkyl peroxide (c2) is preferably di-t-butyl peroxide.

[0069] As the radical generator, it is particularly preferred to use t-butylperoxyisopropyl carbonate as the peroxyester (c1) and di-t-butyl peroxide as the dialkyl peroxide (c2).

[0070] The amount of radical generator used, i.e., the amount blended into the raw material mixture subjected to modification treatment, is usually 0.001 parts by mass or more, preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and usually 5 parts by mass or less, preferably 3 parts by mass or less, more preferably 2 parts by mass or less, per 100 parts by mass of raw material polypropylene. When the amount of radical generator blended is equal to or greater than the above-mentioned lower limit, the modification reaction is likely to occur sufficiently. When the amount of radical generator blended is equal to or less than the above-mentioned upper limit, a significant decrease in material strength due to promotion of low molecular weight (viscosity reduction) of polypropylene can be suppressed.

[0071] When peroxyesters (c1) and dialkyl peroxides (c2) are used in combination as radical generators, it is preferable to blend 0.2 parts by mass or more and 1.0 parts by mass of peroxyesters (c1) and 0.05 parts by mass or more and 0.5 parts by mass or less of dialkyl peroxides (c2) per 100 parts by mass of raw material polypropylene, so that the total of these amounts corresponds to the blending amount of the radical generators described above.

[0072] <Modification Treatment> Any known method can be used for the step of modifying raw material polypropylene with unsaturated carboxylic acid and / or its derivative (d). As the modification treatment method, a melt-kneading reaction method, a solution reaction method, or a suspension-dispersion reaction method can be used. Usually, the melt-kneading reaction method is preferred.

[0073] In the case of the melt-kneading reaction method, the raw material polypropylene, preferably polypropylene (a), more preferably a mixture of polypropylene (a) and polypropylene (b), unsaturated carboxylic acid and / or its derivative (b), and preferably further peroxyesters (c1) and dialkyl peroxides (c2) as radical generators are uniformly mixed in a predetermined blending ratio, followed by melt-kneading. A Henschel mixer, ribbon blender, V-type blender, or the like is used for mixing. A single-screw or twin-screw extruder, roll, Banbury mixer, kneader, Brabender mixer, or the like can usually be used for melt-kneading. Among these, a twin-screw extruder is particularly preferred.

[0074] The melt-kneading is carried out at a temperature in the range of usually 100°C or higher, preferably 120°C or higher, more preferably 150°C or higher, and usually 300°C or lower, preferably 280°C or lower, more preferably 250°C or lower, so as to prevent thermal degradation of the raw material polypropylene and the resulting modified polypropylene.

[0075] [Adhesive] The adhesive of the present invention contains the polymer composition of the present invention. The adhesive of the present invention may contain a polymer such as unmodified polypropylene, an olefin polymer such as polyethylene, or a polar polymer such as polyamide or nylon, as long as the adhesive properties and heat resistance of the polymer composition of the present invention are not impaired.

[0076] [Aqueous Dispersion Composition] The aqueous dispersion composition of the present invention contains the polymer composition of the present invention, a surfactant, and water as essential components. The aqueous dispersion composition of the present invention may also contain other additives such as a polymer dispersant, a neutralizing agent, and the like.

[0077] [Content of polymer composition] The content of the polymer composition of the present invention in the aqueous dispersion composition of the present invention is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, based on the solid content of the aqueous dispersion composition, from the viewpoint of sufficiently obtaining the adhesiveness and heat resistance due to the modified polypropylene in the polymer composition. On the other hand, the content of the polymer composition of the present invention in the aqueous dispersion composition of the present invention is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less, based on the solid content of the aqueous dispersion composition, from the viewpoint of the viscosity and liquid stability of the aqueous dispersion.

[0078] [Surfactant] The surfactant used in the aqueous dispersion composition of the present invention is not particularly limited, but from the viewpoints of emulsifying properties, safety, and suppression of gelation when various additives are added, it is preferable to use a nonionic surfactant.

[0079] Examples of nonionic surfactants include polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene dodecyl ether, polyoxyethylene myristyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene isostearyl ether, polyoxyethylene behenyl ether, polyoxyethylene-2-ethylhexyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl ether (synthetic), narrow-type polyoxyethylene alkyl ether, polyoxyethylene octyldodecyl ether, polyoxyethylene styrenated phenyl ether, polyoxyethylene β-naphthyl ether, polyoxyethylene hydrogenated castor oil ether, polyethylene glycol monoalkyl fatty acid ester, polyethylene glycol fatty acid ester, and polyoxyethylene sorbitan monolaurate. These may be used alone or in combination of two or more.

[0080] In order to obtain a more stable aqueous dispersion composition, a cationic surfactant, an anionic surfactant, an amphoteric surfactant, or a reactive surfactant may be used in combination with the nonionic surfactant.

[0081] Examples of cationic surfactants include higher alkyl monoamine salts such as dodecylamine acetate and stearylamine acetate; alkyl diamine salts such as N-dodecyl-1,3-diaminopropane adipate and N-dodecylpropylenediamine dioleate; and quaternary ammonium salts such as dodecyltrimethylammonium chloride and behenyltrimethylammonium chloride.

[0082] Examples of anionic surfactants include semi-hardened beef tallow fatty acid soap sodium salt, stearic acid soap sodium salt, oleic acid soap potassium salt, gum rosin-based disproportionated rosin sodium salt, alkenyl succinic acid dipotassium salt, dodecyl sulfate sodium salt, anhydrous sodium bisulfite, polyoxyethylene alkyl (C12, C13) ether sulfate sodium salt, polyoxyethylene dodecyl sulfate ammonium salt, dodecylbenzenesulfonate sodium, and alkylene oxide adducts of higher alcohols (C6 to C28).

[0083] Examples of amphoteric surfactants include carboxybetaine, sulfobetaine, phosphobetaine, amide amino acid, and imidazolinium betaine surfactants.

[0084] Examples of reactive surfactants include compounds having a reactive double bond, such as alkylpropenylphenol polyethylene oxide adducts and sulfate ester salts thereof, allylalkylphenol polyethylene oxide adducts and sulfate ester salts thereof, and allyldialkylphenol polyethylene oxide adducts and sulfate ester salts thereof.

[0085] The surfactant is preferably blended in an amount of 1 to 50% by mass, more preferably 5 to 40% by mass, based on the polymer composition of the present invention. When the blending amount of the surfactant is equal to or greater than the lower limit, the polymer composition of the present invention can be stably dispersed in water for a long period of time. When the blending amount of the surfactant is equal to or less than the upper limit, adhesiveness and heat resistance can be ensured.

[0086] [Polymer Dispersant] Examples of polymer dispersants include polycarboxylic acid polymer dispersants having multiple carboxyl groups in the molecule, polyamine polymer dispersants having multiple amino groups in the molecule, polymer dispersants having multiple amide groups in the molecule, and polymer dispersants containing multiple polycyclic aromatic compounds in the molecule. These may be used alone or in combination of two or more.

[0087] The polymer dispersant is preferably blended in an amount of 0.1 to 10% by mass, more preferably 0.2 to 3% by mass, based on the polymer composition of the present invention. When the blending amount of the polymer dispersant is equal to or greater than the lower limit, the stability of the polymer composition of the present invention can be further improved. When the blending amount of the polymer dispersant is equal to or less than the upper limit, adhesion and heat resistance tend to be easily maintained.

[0088] [Neutralizing Agent] Examples of neutralizing agents include potassium hydroxide, sodium hydroxide, magnesium hydroxide, calcium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, calcium bicarbonate, magnesium carbonate, magnesium bicarbonate, monolaurylamine, trimethylamine, dimethylmonoethanolamine, triethanolamine, ethylenediamine, ammonia, morpholine, N-methylmorpholine, and N-ethylmorpholine. These may be used alone or in combination of two or more. The neutralizing agent can be blended in an appropriate amount depending on the application. The neutralizing agent is preferably blended in an amount of about 0.1 to 10 mass% relative to the total amount of the aqueous dispersion composition.

[0089] [Other Additives] The aqueous dispersion composition of the present invention may further contain additives commonly used in aqueous dispersions as adhesives, such as antioxidants, surface treatment agents, lubricants, slip agents (or texture improvers), antistatic agents (which partly overlap with the above-mentioned surfactants), pH adjusters (which partly overlap with the above-mentioned neutralizing agents), ultraviolet absorbers, light stabilizers, heat stabilizers, antifoaming agents, antioxidants, and leveling agents, in usual blending amounts.

[0090] Examples of antioxidants include phenolic antioxidants such as hydroquinone, methoxyhydroquinone, catechol, 2,6-di-t-butyl-p-cresol (BHT), and 2,2'-methylenebis(4-methyl-6-t-butylphenol); thiourea, tetramethylthiuram disulfide, dimethyldithiocarbamic acid and its salts, sodium sulfite, sodium thiosulfate, 2-mercaptobenzothiazole and its salts, and dilauryl 3,3'-thiodipropionate (DL sulfur-containing compounds such as triphenyl phosphite, triethyl phosphite, sodium phosphite, sodium hypophosphite, triphenyl phosphite (TPP), triisodecyl phosphite (TDP), and the like; and nitrogen-containing compounds such as octylated diphenylamine, N-n-butyl-p-aminophenol, N,N-diisopropyl-p-phenylenediamine, urea, and guanidine.

[0091] Examples of surface treatment agents include coupling agents such as aminosilane coupling agents, epoxysilane coupling agents, vinylsilane coupling agents, methacrylosilane coupling agents, ureidosilane coupling agents, borane coupling agents, titanate coupling agents, aluminum coupling agents, chromium coupling agents, and zirconium coupling agents; and colloidal gels such as colloidal silica and colloidal alumina.

[0092] Examples of lubricants include hydrogenated and hardened animal and vegetable oils, paraffin wax, and ester-based synthetic oils.

[0093] Examples of lubricants (or texture improvers) include butyl stearate, tetraethylenepentamine distearate, hydrogenated castor oil, imidazoline-based fatty acid amides, cationic fatty acid amides, cationic polyethyleneimine polyamides, and bisphenol A poly(oxyethylene) ether glycols.

[0094] Examples of the antistatic agent include various surfactants such as anionic surfactants and cationic surfactants.

[0095] Examples of pH adjusters include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, and organic acids such as citric acid, succinic acid, malic acid, and lactic acid; and alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, monoethanolamine, diethanolamine, and triethanolamine.

[0096] Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, triazine-based ultraviolet absorbers, cyclic iminoester-based ultraviolet absorbers, and phenyl salicylate-based ultraviolet absorbers.

[0097] Examples of the light stabilizer include hindered amine light stabilizers such as 2,2,6,6-tetramethyl-4-piperidyl stearate and 1,2,2,6,6-pentamethyl-4-piperidyl stearate.

[0098] [Organic Solvent] The aqueous dispersion composition of the present invention uses water as a dispersion medium, but may contain a water-soluble organic solvent as needed.

[0099] In this case, examples of organic solvents that can be used include alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, t-butyl alcohol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, t-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butyl alcohol, n-hexyl alcohol, and cyclohexyl alcohol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, and cyclohexanone; ethers such as tetrahydrofuran and dioxane; esters such as ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, ethyl propionate, diethyl carbonate, and dimethyl carbonate; and glycol derivatives such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and ethylene glycol ethyl ether acetate. Other organic solvents that can be used include 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 3-methoxy-3-methyl-1-butanol, methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate, 1,2-dimethylglycerin, 1,3-dimethylglycerin, trimethylglycerin, etc. These organic solvents may be used alone or in combination of two or more.

[0100] When an organic solvent is used, the amount of the organic solvent is not particularly limited, but the amount of the organic solvent is preferably 0 to 10% by mass based on the total amount of the aqueous medium.

[0101] [Solid content concentration] The solid content concentration of the aqueous dispersion composition of the present invention, i.e., the total concentration of components other than water (which may be an aqueous medium of water and an organic solvent), is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, from the viewpoint of ensuring an effective amount of adhesive after application of the aqueous dispersion. On the other hand, from the viewpoint of the liquid stability and application properties of the aqueous dispersion, the solid content concentration of the aqueous dispersion composition of the present invention is preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less.

[0102] [Average particle size] The average particle size of the dispersed particles of the modified polypropylene in the aqueous dispersion composition of the present invention can be adjusted as desired depending on the application, and is not particularly limited. The average particle size of the dispersed particles is preferably 50 to 1,000 nm, particularly preferably 100 to 300 nm, for applications such as building materials and automobiles.

[0103] [pH] The pH of the aqueous dispersion composition of the present invention is preferably 6 or more, more preferably 6.5 or more, from the viewpoint of liquid stability of the aqueous dispersion, and is preferably 12 or less, more preferably 11.5 or less.

[0104] [Method for producing aqueous dispersion composition] The method for producing the aqueous dispersion composition of the present invention is not particularly limited. The aqueous dispersion composition of the present invention can be obtained, for example, by charging the polymer composition of the present invention, a surfactant, an aqueous medium, and, if necessary, a polymer dispersant, a neutralizing agent, etc., into a pressurizable device having normal shear force such as an autoclave, heating the mixture to a temperature near or above the softening temperature of the modified polypropylene in the polymer composition of the present invention, and stirring the mixture. Here, the aqueous medium is a liquid containing water as a main component, and may contain the above-mentioned water-soluble organic solvent.

[0105] More specifically, the polymer composition of the present invention, a surfactant, a polymer dispersant, other additives other than the neutralizing agent, and water are added to an autoclave having emulsification equipment equipped with a stirrer, a thermometer, and a temperature controller, and the mixture is heated to about 160 to 200°C while stirring at 100 to 1500 rpm to finely disperse the polymer composition to the aforementioned suitable dispersed particle size. The mixture is then cooled to room temperature to about 80°C, and a neutralizing agent is added as needed to adjust the pH to the aforementioned suitable pH. Water may be further added as needed to adjust the solids concentration.

[0106] [Uses] The adhesive of the present invention and the aqueous dispersion composition of the present invention can be effectively used in the fields of building materials and automobiles for bonding adherends with low polarity, such as ABS, to metals or adherends with high polarity, particularly due to their excellent adhesiveness and heat resistance.

[0107] Specific embodiments of the present invention will be described in more detail below using examples. The present invention is not limited to the following examples as long as it does not deviate from the gist of the invention. The values ​​of various production conditions and evaluation results in the following examples represent preferred upper or lower limit values ​​in the embodiments of the present invention, and a preferred range may be defined by a combination of the above-mentioned upper or lower limit values ​​and the values ​​in the following examples or values ​​between the examples.

[0108] [Raw Materials] In the following Examples and Comparative Examples, the raw materials used for preparing modified polypropylene, which is a polymer composition, are as follows.

[0109] <Polypropylene (a)> a-1: Propylene-ethylene copolymer WINTEC (registered trademark) WMG03 manufactured by Japan Polypropylene Corporation (flexural modulus: 1250 MPa, MFR (230 ° C, load 2.16 kg): 30 g / 10 min, density: 0.900 g / cm ３ a-2: Propylene-ethylene copolymer WINTEC (registered trademark) WFW4M manufactured by Japan Polypropylene Corporation (flexural modulus: 900 MPa, MFR (230 ° C, load 2.16 kg): 7 g / 10 min, density: 0.900 g / cm ３ )

[0110] <Polypropylene (d)> d-1: Propylene-ethylene copolymer Vistamaxx (registered trademark) 3020FL manufactured by EXXON Mobil (flexural modulus: 47 MPa, MFR (230 ° C, load 2.16 kg): 2 g / 10 min, density: 0.873 g / cm ３ d-2: Propylene-ethylene copolymer Vistamaxx (registered trademark) 6102 manufactured by EXXON Mobil (flexural modulus: 11 MPa, MFR (230 ° C, load 2.16 kg): 3 g / 10 min, density: 0.862 g / cm ３ d-3: Propylene-ethylene copolymer Vistamaxx (registered trademark) 8880 manufactured by EXXON Mobil (viscosity (190 ° C): 1200 cP, density: 0.879 g / cm ３ )

[0111] <Unsaturated Carboxylic Acid and / or Derivative Thereof (b)> Maleic Anhydride (Commercially Available Product)

[0112] <Radical Generators> C-1: t-butylperoxyisopropyl carbonate, a peroxyester (c1), manufactured by NOF Corporation, Perbutyl I C-2: di-t-butyl peroxide, a dialkyl peroxide (c2), manufactured by NOF Corporation, Perbutyl D C-3: t-butylperoxy-2-ethylhexanoate, a peroxyester (c1), manufactured by NOF Corporation, Perbutyl O

[0113] [Preparation and Evaluation of Polymer Composition] Example 1 100 parts by mass of component (a-1), 0.6 parts by mass of component (C-1), 0.2 parts by mass of component (C-2), and 1.5 parts by mass of component (b), maleic anhydride, were dry blended and mixed, and the mixture was melt-kneaded using a twin-screw extruder (manufactured by The Japan Steel Works, Ltd., TEX25αIII, D=25 mmφ, L / D=52.5) ​​at a set temperature of 230°C, a screw rotation speed of 400 rpm, and an extrusion rate of 20 kg / h, and strand cut to obtain pellets of modified polypropylene modified with maleic anhydride. The modified polypropylene pellets obtained were measured for the mass percentage X1 (mass%), which is the content (X1) of unsaturated carboxylic acid and / or derivatives thereof before acetone extraction, the mass percentage X2 (mass%), which is the content (X2) of unsaturated carboxylic acid and / or derivatives thereof after acetone extraction, and MFR (180°C, 2.16 kg) by the methods described above, and the YI, adhesiveness, and heat resistance were also evaluated by the following methods. The results are shown in Table 1.

[0114] Examples 2 to 7, Comparative Examples 1 to 6 Modified polypropylenes were obtained and evaluated in the same manner as in Example 1, except that the blending compositions were changed as shown in Table 1. The results are shown in Table 1.

[0115] <Evaluation Method> (1) YI The YI of the modified polypropylene pellets was measured using a commercially available color difference meter (for example, the ZE series manufactured by Nippon Denshoku Industries Co., Ltd.) The measurement was carried out three times, and the average value was taken as the YI value.

[0116] (2) Adhesion A 100 mm square, 1 mm thick sheet was prepared from the modified polypropylene using a heat press under conditions of a set temperature of 200°C, 10 MPa, and 2 minutes. The obtained sheet was then bonded to a 100 mm square glass plate, and a heat press was used to prepare an adhesion sample under conditions of a set temperature of 200°C, 5 MPa, and 3 minutes. The obtained adhesion sample was cut into a width of 15 mm using a cutter to obtain a test piece, and a 90° peel test was performed at a speed of 50 mm / min in an atmosphere of 23°C to measure the adhesion strength. The obtained measured values ​​were evaluated according to the following criteria: ○: 10 N / 15 mm or more △: 5 N / 15 mm or more, less than 10 N / 15 mm ×: less than 5 N / 15 mm

[0117] (3) Heat Resistance A 100 mm square, 1 mm thick sheet was prepared from the modified polypropylene using a heat press under conditions of a set temperature of 200°C, 10 MPa, and 2 minutes. A 20 mm square sample was cut out from this sheet and heated in an oven at 200°C for 30 minutes. After heating, the sample was removed from the oven, and the degree of discoloration of the sample before and after heating was evaluated by visual observation. Small discoloration was marked with ◯, and large discoloration was marked with ×.

[0118]

[0119] <Discussion> As shown in Table 1, in Examples 1 to 7, which used a combination of the peroxyester (c1) Perbutyl I (C-1) and the dialkyl peroxide (c2) Perbutyl D (C-2) as radical generators, the reaction rate of maleic anhydride was high, and therefore the content (X1-X2) of unsaturated carboxylic acid and / or its derivative present as a simple substance, which is the amount of maleic anhydride residue, was very low. Furthermore, the modified polypropylene had a low YI and excellent color tone. The modified polypropylene produced in this way had good adhesion and excellent heat resistance, and therefore showed little change in color tone after heat resistance testing.

[0120] In Comparative Examples 1 to 3, in which only Perbutyl O, a peroxyester (c1), was used as the radical generator, the amount of maleic anhydride residue, i.e., the content (X1-X2) of unsaturated carboxylic acid and / or its derivative present as a simple substance, was large, resulting in poor adhesion and a large change in color tone after the heat resistance test.

[0121] In Comparative Example 4, in which 1.4 parts by mass of Perbutyl I (C-1) and 0.8 parts by mass of Perbutyl D (C-2) were used as radical generators, the content (X2) of unsaturated carboxylic acid and / or derivative thereof graft polymerized onto the modified polypropylene contained in the polymer composition was high, resulting in a large change in color tone after the heat resistance test. In Comparative Example 5, in which only Perbutyl D (C-2) was used as the radical generator, the content (X2) of unsaturated carboxylic acid and / or derivative thereof graft polymerized onto the modified polypropylene contained in the polymer composition and the amount of maleic anhydride residue, i.e., the content (X1-X2) of unsaturated carboxylic acid and / or derivative thereof present as a simple substance, were both high, and the MFR was also large, resulting in poor adhesion and a large change in color tone after the heat resistance test. In Comparative Example 6, in which 0.4 parts by mass of Perbutyl I (C-1) and 0.3 parts by mass of Perbutyl D (C-2) were used in combination as radical generators, the amount of maleic anhydride residue, i.e., the content (X1-X2) of unsaturated carboxylic acid and / or its derivative present as a simple substance, was high, resulting in poor adhesion and a large change in color tone after the heat resistance test.

[0122] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications are possible within the scope of the effects of the invention. This application is based on Japanese Patent Application No. 2022-153904 filed on September 27, 2022, the entire contents of which are incorporated by reference.

Claims

1. A polymer composition containing modified polypropylene modified with at least one selected from the group consisting of unsaturated carboxylic acids and their derivatives, The difference (X1 - X2) between the mass percentage X1 (mass%) defined below and the mass percentage X2 (mass%) defined below is 0.01 mass% or more and 0.5 mass% or less. The following mass percentage X2 (mass%) is 0.7% by mass or more and 1.8% by mass or less. A polymer composition whose MFR is 1 g / 10 min or more and 40 g / 10 min or less, as measured in accordance with JIS K7210 under the conditions of 180°C, 2.16 kg load, and 1 mm orifice. Mass ratio X1 (mass%): A circular sheet obtained by press-molding the polymer composition into a circular sheet with a thickness of 100 μm and a diameter of 20 mm under the conditions of 200°C, 5 MPa, and 3 min is used as the measurement sample, and the measurement is performed by infrared absorption spectroscopy at 1900 to 1600 cm⁻¹. －１ The mass ratio (mass%) of the total mass of the unsaturated carboxylic acid and / or its derivative graft polymerized onto polypropylene in the sample and the mass of the unsaturated carboxylic acid and / or its derivative present in the sample in its elemental form, calculated using a calibration curve from the measured carbonyl characteristic absorption of the sample, is calculated as follows: Mass ratio X2 (mass%): The polymer composition is press-molded into a circular sheet with a thickness of 100 μm and a diameter of 20 mm at 200°C, 5 MPa, and 3 minutes. The resulting circular sheet is placed in a Soxhlet extractor, refluxed with acetone at 80°C for 1 hour, and then dried at 80°C for 2 hours. The resulting circular sheet is used as the sample for infrared absorption spectroscopy, and the measurement is performed using infrared absorption spectroscopy at 1900 to 1600 cm⁻¹. －１ The mass percentage (mass%) of the unsaturated carboxylic acid and / or its derivative graft-polymerized onto polypropylene in the sample, calculated using a calibration curve based on the measured carbonyl characteristic absorption of the sample.

2. The polymer composition according to claim 1, wherein the MFR measured in accordance with JIS K7210 at 180°C, with a load of 2.16 kg and a 1 mm orifice is 5 g / 10 min or more and 40 g / 10 min or less.

3. The polymer composition according to claim 1 or 2, which is a polymer composition for aqueous dispersions.

4. A method for producing a polymer composition according to claim 1, comprising the step of reacting a raw material polypropylene (a) having a flexural modulus of 100 MPa or more and 2000 MPa or less with an unsaturated carboxylic acid and / or a derivative thereof (b) in the presence of t-butyl peroxyisopropyl carbonate and dialkyl peroxides (c2).

5. A method for producing the polymer composition according to claim 4, wherein the dialkyl peroxides (c2) are di-t-butyl peroxide.

6. The method for producing the polymer composition according to claim 4, wherein the total amount of t-butyl peroxyisopropyl carbonate and the dialkyl peroxides (c2) is 0.001 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the raw material polypropylene.

7. A method for producing the polymer composition according to claim 4, comprising blending 0.2 parts by mass or more and 1.0 part by mass of t-butyl peroxyisopropyl carbonate and 0.05 parts by mass or more and 0.5 parts by mass of dialkyl peroxides (c2) with 100 parts by mass of raw material polypropylene.

8. A method for producing a polymer composition according to claim 4, wherein the raw material polypropylene further comprises polypropylene (d) having a flexural modulus of less than 100 MPa or a viscosity at 190°C of 100 cP or more and 3000 cP or less.

9. A method for producing the polymer composition according to claim 4, wherein the content of polypropylene (a) is 50% by mass or more and 100% by mass or less with respect to 100% by mass of the raw material polypropylene.

10. A method for producing the polymer composition according to claim 8, wherein the content of polypropylene (d) is 1% by mass or more and 50% by mass or less with respect to 100% by mass of the raw material polypropylene.

11. An adhesive comprising the polymer composition according to claim 1 or 2.

12. An aqueous dispersion composition comprising the polymer composition according to claim 1 or 2, a surfactant, and water.

13. The aqueous dispersion composition according to claim 12, wherein the content of the polymer composition in the aqueous dispersion composition is 40% by mass or more and 95% by mass or less with respect to the solid content of the aqueous dispersion composition.

14. The aqueous dispersion composition according to claim 12, wherein the solid content concentration of the aqueous dispersion composition is 5% by mass or more and 60% by mass or less.