Acid scavengers and resin compositions

Abstract

The objective is to provide an acid scavenger that exhibits excellent dispersibility in (co)polymers containing vinyl chloride monomer as a constituent monomer. [Solution] An acid scavenger comprising a copolymer (A) having a glycidyl group (meth)acrylate and a radical polymerizable monomer represented by general formula (1) as essential constituent monomers, and a copolymer (P) having vinyl chloride as an essential constituent monomer and having at least one functional group selected from the group consisting of a sulfonic acid (salt) group, a carboxylic acid (salt) group, and a phosphoric acid (salt) group, and a chlorine atom-containing resin composition comprising the above acid scavenger. TIFF2026139211000007.tif40152 [In general formula (1), A represents an oxygen atom or NH. B represents an alkylene group having 1 to 4 carbon atoms. R 1 R represents a hydrogen atom or a methyl group. 2 , R 3 and R 4 Each of these independently represents an alkyl group having 1 to 4 carbon atoms. - [This represents a halogen ion.]

Description

[Technical Field]

[0001] The present invention relates to an acid scavenger and a resin composition containing the same. [Background technology]

[0002] Polyvinyl chloride resin is a representative general-purpose resin used in a wide range of fields. However, it is known that when polyvinyl chloride resin is heated for molding or other purposes, a dehydrochlorination reaction occurs due to thermal decomposition, and the resulting hydrogen chloride causes the resin to deteriorate. As a method for capturing hydrogen chloride released from polymers in this manner, a method is known in which a tin-based compound, epoxy compound, metal soap, or phosphite-based compound hydrochloric acid is mixed with the polymer as an acid scavenger (Patent Document 1).

[0003] However, the acid scavenger described in Patent Document 1 had problems such as insufficient dispersibility in copolymers containing vinyl chloride monomer, resulting in poor appearance, and the acid scavenger bleeding out. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2002-179932 [Overview of the project] [Problems that the invention aims to solve]

[0005] This invention has been made in view of the above-mentioned problems, and the object of this invention is to provide an acid scavenger that exhibits excellent dispersibility in (co)polymers containing vinyl chloride monomer as a constituent monomer. [Means for solving the problem]

[0006] The inventors of this invention arrived at the present invention as a result of diligent research to solve the above problems. In other words, the present invention relates to an acid scavenger comprising a copolymer (A) having a glycidyl group (meth)acrylate and a radical polymerizable monomer represented by the following general formula (1) as essential constituent monomers, a copolymer (P) having vinyl chloride as an essential constituent monomer and having at least one functional group selected from the group consisting of a sulfonic acid (salt) group, a carboxylic acid (salt) group, and a phosphoric acid (salt) group, and the above-mentioned acid scavenger.

[0007] [ka] [In general formula (1), A represents an oxygen atom or NH. B represents an alkylene group having 1 to 4 carbon atoms. R 1 R represents a hydrogen atom or a methyl group. 2 , R 3 and R 4 Each of these independently represents an alkyl group having 1 to 4 carbon atoms. - [This represents a halogen ion.] [Effects of the Invention]

[0008] The acid scavenger of the present invention can capture hydrogen chloride released from polymers by mixing it with resins containing chlorine atoms, such as (co)polymers containing vinyl chloride monomer as a constituent monomer, without deterioration of appearance due to bleed-out of the added acid scavenger component. [Modes for carrying out the invention]

[0009] The first invention of this application is an acid scavenger comprising a copolymer (A) in which a (meth)acrylate having a glycidyl group and a radical polymerizable monomer represented by the following general formula (1) are essential constituent monomers.

[0010] [ka] [In general formula (1), A represents an oxygen atom or NH. B represents an alkylene group having 1 to 4 carbon atoms. R 1represents a hydrogen atom or a methyl group. R 2 , R 3 and R 4 each independently represent an alkyl group having 1 to 4 carbon atoms. X - represents a halogen ion.]

[0011] Examples of the (meth)acrylate having a glycidyl group, which is an essential constituent monomer of the copolymer (A), include glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, and glycidyl acrylate and glycidyl methacrylate are preferred from the viewpoint of acid scavenging ability.

[0012] The copolymer (A) contains, together with the (meth)acrylate having a glycidyl group described above, a radically polymerizable monomer represented by the following general formula (1) as an essential constituent monomer.

[0013]

Chemical Formula

[0014] In general formula (1), A represents an oxygen atom or NH (imino group).

[0015] In general formula (1), B represents an alkylene group having 1 to 4 carbon atoms, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an n-butylene group.

[0016] In general formula (1), R 1 represents a hydrogen atom or a methyl group.

[0017] In general formula (1), R 2 , R 3 and R 4 each independently represent an alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an isopropyl group, a 2-methylpropyl group, a 2-methylpropan-2-yl group, and a 2-butyl group, with a methyl group and an ethyl group being preferred. R 2 , R 3 and R4 These may all be the same, or they may all be different, but it is preferable that they all be the same.

[0018] In general formula (1), X - represents a halogen ion, and preferred halogen ions include Cl - , Br - , or I - These include Cl - That is even more preferable.

[0019] Examples of radical polymerizable monomers represented by general formula (1) include (meth)acryloyloxyalkyltrialkylammonium salts and (meth)acryloylaminoalkyltrialkylammonium salts. Examples of (meth)acryloyloxyalkyltrialkylammonium salts include acryloyloxyethyltrimethylammonium chloride and methacryloyloxyethyltrimethylammonium chloride. Examples of (meth)acryloylaminoalkyltrialkylammonium salts include (3-acrylamidopropyl)trimethylammonium chloride and [3-(methacryloylamino)propyl]trimethylammonium chloride. These may be used individually or in combination of two or more types. As the radical polymerizable monomer represented by general formula (1), (meth)acryloyloxyalkyltrialkylammonium salts are preferred from the viewpoint of bleed-out of acid scavengers, and methacryloyloxyethyltrimethylammonium chloride is more preferred.

[0020] Copolymer (A) may contain as constituent monomers a (meth)acrylate having a glycidyl group and monomers other than the radical polymerizable monomer represented by the general formula (1) above (hereinafter referred to as "other monomers"). Other monomers include aromatic vinyl monomers, nitrogen atom-containing monomers other than those in which B in general formula (1) is an imino group (hereinafter referred to as nitrogen atom-containing monomers), and hydroxyl group-containing monomers.

[0021] Examples of aromatic vinyl monomers include styrene, substituted styrenes in which the hydrogen atoms of the benzene ring are replaced with hydrocarbyl (alkyl, cycloalkyl, aralkyl, and / or alkenyl) groups having 1 to 7 carbon atoms (such as α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene, cyclohexylstyrene, and benzylstyrene), and hydroxyl group-containing styrene compounds having 8 to 15 carbon atoms in which the hydrogen atoms of the benzene ring are replaced with hydroxyl groups (such as hydroxystyrene).

[0022] Examples of nitrogen atom-containing monomers include acrylamide monomers (a1) and amino group-containing monomers (a2).

[0023] Acrylamide monomers (a1) include those having one (meth)acryloyl group, such as (meth)acrylamide and (meth)acrylamide containing an amino group with 5 to 10 carbon atoms. Examples of (meth)acrylamides containing amino groups with 5 to 10 carbon atoms include N-aminoalkyl (1 to 6 carbon atoms) (meth)acrylamides. Examples of N-aminoalkyl (1-6 carbon atoms) (meth)acrylamides include N-methyl(meth)acrylamide and N-aminoethyl(meth)acrylamide.

[0024] The amino group-containing monomer (a2) includes amino group-containing (meth)acrylates with 5 to 15 carbon atoms that have one (meth)acryloyl group other than (a1), and examples include aminoalkyl (1 to 6 carbon atoms) (meth)acrylate, alkyl (1 to 6 carbon atoms) aminoalkyl (1 to 6 carbon atoms) (meth)acrylate, dialkyl (1 to 4 carbon atoms of alkyl) aminoalkyl (1 to 4 carbon atoms) (meth)acrylate, etc. Examples of aminoalkyl (1-6 carbon atoms) (meth)acrylates include aminoethyl (meth)acrylate and aminopropyl (meth)acrylate. Examples of alkyl (1-6 carbon atoms) aminoalkyl (1-6 carbon atoms) (meth)acrylates include t-butylaminoethyl methacrylate. Examples of dialkyl (alkyl with 1 to 4 carbon atoms) aminoalkyl (with 1 to 4 carbon atoms) (meth)acrylates include dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate.

[0025] Examples of hydroxyl group-containing monomers include those having one (meth)acryloyl group, such as hydroxyalkyl (1-6 carbon atoms) (meth)acrylates and hydroxyl group-containing monomers having a poly(n=2-30) oxyalkylene (oxyalkylene group with 2-4 carbon atoms) chain. Examples of hydroxyalkyl (1-6 carbon atoms) (meth)acrylates include hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate. Examples of hydroxyl group-containing monomers having a poly(n=2~30)oxyalkylene (oxyalkylene group with 2~4 carbon atoms) chain include polyoxyethylene mono(meth)acrylate.

[0026] In copolymer (A), the weight percentage of constituent units based on (meth)acrylate having a glycidyl group is preferably 40 to 99.9% by weight, based on the total weight of constituent monomers of copolymer (A), from the viewpoint of the acid scavenging ability of the acid scavenger.

[0027] In copolymer (A), the weight percentage of constituent units based on the radical polymerizable monomer represented by general formula (1) is preferably 0.1 to 50% by weight, based on the total weight of the constituent monomers of copolymer (A), from the viewpoint of bleed-out of the acid scavenger.

[0028] In copolymer (A), the weight percentage of other monomers in the total constituent monomers is preferably 10% by weight or less, and more preferably 5% by weight or less, based on the weight of copolymer (A), from the viewpoint of the acid scavenging ability of the acid scavenger.

[0029] Copolymer (A) can be obtained by polymerizing a monomer composition containing a (meth)acrylate having a glycidyl group and a radical polymerizable monomer represented by general formula (1) using known methods, and can be obtained by known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. Among these methods, solution polymerization can be preferably used.

[0030] As a method for obtaining copolymer (A) by solution polymerization, a method of polymerizing by dropwise adding the monomer composition and an essential polymerization initiator to a solvent can be preferably used. In solution polymerization, the polymerization temperature is preferably 70 to 230°C, and more preferably 80 to 180°C, from the viewpoint of protecting the glycidyl group.

[0031] The weight-average molecular weight of copolymer (A) is preferably 1,000 to 100,000, and more preferably 3,000 to 30,000, from the viewpoint of the strength of the thermoplastic resin composition containing the acid scavenger.

[0032] The weight-average molecular weight of copolymer (A) is measured by dissolving copolymer (A) in tetrahydrofuran (THF) and using this as the sample solution, under the following conditions using gel permeation chromatography (GPC). Equipment: HLC-8120 manufactured by Tosoh Corporation Column: TSK GEL GMH6 (2 pieces) [Manufactured by Tosoh Corporation] Measurement temperature: 40℃ Sample solution: 0.25% by weight THF solution Solution injection volume: 100μL Detection device: Refractive index detector Reference material: Tosoh standard polystyrene [TSKstandard POLYSTYRENE] 12 points (molecular weight: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, 2,890,000)

[0033] The concentration of glycidyl groups (moles / kg) in copolymer (A) is preferably 0.1 to 7.0 mol / kg, and more preferably 2.5 to 6.5 mol / kg, based on the weight of copolymer (A), from the viewpoint of the acid scavenging ability of the acid scavenger. The epoxy group concentration can be determined from the epoxy equivalent (g / eq) measured according to the method compliant with JIS K 7236 using the following formula. Epoxy group concentration (moles / kg) = 1,000 / epoxy equivalent

[0034] The acid scavenger of the present invention may also contain known resin additives (such as colorants, antioxidants, ultraviolet absorbers, granulators, and antistatic agents) in addition to the copolymer (A). The weight percentage of copolymer (A) contained in the acid scavenger of the present invention is preferably 90% by weight or more, and more preferably 95% by weight or more, based on the weight of the acid scavenger. The acid scavenger containing the aforementioned resin additive can be obtained by a known method of melt-kneading the copolymer (A) and the resin additive, or by a known method of powder mixing.

[0035] While there are no restrictions on the shape of the acid scavenger of the present invention, from the viewpoint of dispersibility in thermoplastic resins, it is preferable that it be in the form of parts with a weight-average particle diameter of 10 mm or less, and more preferably 4 mm or less. The acid scavenger of the present invention can be made into particles by grinding the copolymer (A) using a known method such as a pulverizer, and the particle size can be adjusted to a preferred weight-average particle size by classifying it using a known method such as sieving. The weight-average particle size can be measured using a method compliant with JIS Z8815 General Rules for Sieve Analysis Tests.

[0036] The acid scavenger of the present invention, when mixed with a resin containing chlorine atoms, such as polyvinyl chloride resin, can capture hydrogen chloride generated when the chlorine atom-containing resin is heated, thereby preventing the deterioration of the resin due to hydrogen chloride. In particular, when the resin containing chlorine atoms that is mixed with the acid scavenger is a resin having anionic functional groups, the anionic functional groups of the resin react with the cationic groups of copolymer (A) contained in the acid scavenger, resulting in good dispersion of copolymer (A) in the resin. This is thought to improve not only the appearance and suppression of bleed-out, but also the ability to scavenge hydrogen chloride.

[0037] The second invention of this application is a resin composition comprising a copolymer (P) having vinyl chloride as an essential constituent monomer and at least one functional group selected from the group consisting of a sulfonic acid (salt) group, a carboxylic acid (salt) group, and a phosphoric acid (salt) group, and the aforementioned acid scavenger. Note that a sulfonic acid (salt) group means a sulfonic acid group or a sulfonic acid base, a carboxylic acid (salt) group means a carboxylic acid group or a carboxylic acid base, and a phosphoric acid (salt) group means a phosphate group or a phosphate base.

[0038] Examples of copolymers (P) include copolymers in which a monomer having at least one functional group selected from the group consisting of a sulfonic acid (salt) group, a carboxylic acid (salt) group, and a phosphoric acid (salt) group, and vinyl chloride are essential constituent monomers.

[0039] Examples of monomers having a sulfonic acid (salt) group include 2-acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, styrenesulfonic acid, and their salts (alkali metal salts or ammonium salts).

[0040] Examples of monomers having a carboxylic acid (salt) group include (meth)acrylic acid, 4-vinylbenzoic acid, and their salts (alkali metal salts or ammonium salts).

[0041] Examples of monomers having a phosphate (salt) group include (meth)acryloyloxyalkyl phosphate, (meth)acryloyloxypolypropylene glycol phosphate, vinylphosphonic acid, and salts thereof (alkali metal salts or ammonium salts).

[0042] The copolymer (P) may consist of monomers having at least one functional group selected from the group consisting of sulfonic acid (salt) groups, carboxylic acid (salt) groups, and phosphoric acid (salt) groups, as well as monomers other than vinyl chloride. Examples of monomers that can be preferably used as constituent monomers of copolymer (P) include 2-hydroxypropyl acrylate, vinyl acetate, and acrylonitrile.

[0043] Copolymer (P) can be obtained by polymerizing a monomer composition consisting of vinyl chloride, a monomer having at least one functional group selected from the group consisting of a sulfonic acid (salt) group, a carboxylic acid (salt) group, and a phosphoric acid (salt) group, and other monomers used as needed, by known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. Among these methods, emulsion polymerization can be preferably used.

[0044] As a copolymer (P) having vinyl chloride as an essential constituent monomer and at least one functional group selected from the group consisting of sulfonic acid bases, carboxylic acid bases, and phosphate bases, copolymers described in Japanese Patent Publication No. 7-118594 and Japanese Patent Publication No. 2001-302707 can also be used.

[0045] The resin composition of the present invention can be obtained by mixing the acid scavenger and copolymer (P) by a known method (preferably by dissolving and mixing using an organic solvent). In the resin composition of the present invention, the cationic groups of copolymer (A) react with the anionic groups of copolymer (P), allowing copolymer (A) to be highly dispersed in copolymer (P). This improves the hydrogen chloride scavenging ability and suppresses bleed-out, preventing deterioration of appearance.

[0046] The ratio of the acid scavenger to the copolymer (P) in the resin composition of the present invention can be adjusted according to the amount of chlorine atoms contained in the copolymer (P) and the concentration of glycidyl groups in the acid scavenger. However, from the viewpoint of the resin strength and hydrogen chloride scavenging ability of the resulting resin composition, the amount of acid scavenger mixed with copolymer (P) is preferably such that the weight ratio of copolymer (A) to the weight of copolymer (P) is 0.1 to 10% by weight, and more preferably 0.5 to 5% by weight.

[0047] The resin composition of the present invention is not limited in shape and may be in any form, such as molded articles, fibers, and particles. [Examples]

[0048] The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited thereto. In the examples, "parts" means parts by weight.

[0049] <Examples 1-8, Comparative Example 1> A monomer composition was prepared by mixing the amount by weight of a (meth)acrylate having a glycidyl group, as described in the composition of copolymer (A) in Table 1, with methacryloyloxyethyltrimethylammonium chloride and a polymerization initiator. Sixty parts by weight of isopropanol were charged into a pressure-resistant reaction vessel equipped with a thermometer, stirrer, reflux condenser, and nitrogen inlet. The air in the reaction vessel was replaced with nitrogen gas under stirring, and then the vessel was heated under reflux. Next, after raising the temperature until boiling, the monomer composition was added dropwise over 3 hours under stirring, and then the polymerization reaction was carried out by continuing stirring at the same temperature for 1 hour. Subsequently, the polymerization solvent, isopropanol, was removed by vacuum desolvation and distillation to obtain copolymers (A-1) to (A-8) and (ratio A-1) according to Examples 1 to 8 and Comparative Example 1. The physical properties of the obtained copolymers (A-1) to (A-8) and (ratio A-1) are shown in Table 1. The obtained copolymers (A-1) to (A-8) and (ratio A-1) were used as acid scavengers in Examples 1 to 8 and Comparative Example 1, and were used in Examples 9 to 16 and Comparative Example 2 below.

[0050] [Table 1]

[0051] Note that the (meth)acrylates having a glycidyl group and (meth)acrylates having an ammonium base listed in Table 1 refer to the following compounds. <(meth)acrylate containing a glycidyl group> GMA: Glycidyl methacrylate <(meth)acrylate containing an ammonium base> DMC: Methacryloyloxyethyltrimethylammonium chloride

[0052] <Manufacturing Example 1> In a pressure-resistant reaction vessel equipped with a thermometer, stirrer, reflux condenser, and nitrogen inlet, 52 parts of vinyl chloride, 46 parts of acrylonitrile, 2 parts of sodium styrene sulfonate, and 700 parts of water were charged, and sodium alkylbenzene sulfonate was added to emulsify the mixture. Ammonium persulfate and sodium acidic sulfite were added as polymerization initiators, and emulsion polymerization was carried out at a reaction temperature of 43°C for a polymerization time of 5 hours to obtain 800 parts of acrylic copolymer (P-1), which is copolymer (P) according to claim 2 of this application.

[0053] <Example 9> 800 parts of acrylic copolymer (P-1) were dissolved in dimethyl sulfoxide (DMSO), and 1 part of the acid scavenger [polymer (A-1)] obtained in Example 1 was added to prepare a spinning stock. This spinning stock was extruded using a spinning nozzle into a coagulation bath of 52% by weight DMSO aqueous solution at 20°C, wet-spun, and then stretched in a stretching bath of 30% by weight DMSO aqueous solution at 90°C. Subsequently, it was washed with hot water at 80°C. Next, the primary stretched yarn after washing was immersed for 3 to 5 seconds in an oil bath (60°C) containing a fiber treatment agent (total concentration of 6% by weight of fatty acid ester oil and polyoxyethylene surfactant) to impregnate the yarn with the fiber treatment agent. After drying at 140°C, it was stretched and subjected to a 20% relaxation treatment at 160°C to obtain a fibrous resin composition consisting of acrylic copolymer and acid scavenger.

[0054] <Examples 10-16, Comparative Example 2> Except for changing the acid scavenger obtained in Example 1 to the acid scavenger obtained in Examples 2 to 8 and Comparative Example [polymer (A-2) to (A-8), or (ratio A-1)], the fibrous resin compositions of Examples 10 to 16 and Comparative Example 2 were obtained in the same manner as in Example 9.

[0055] The fibers obtained in Examples 9-16 and Comparative Example 2 were evaluated for their appearance and the presence or absence of acid scavenging bleed-out using the following method, and the results are shown in Table 2.

[0056] <Exterior> The fibers were visually inspected, and a circle (○) was used if they were not colored, and a cross (×) was used if they were colored, as indicated in Table 2.

[0057] <Presence or absence of bleed-out by the acid scavenger> When touching the fibers with bare hands, a circle (○) was used if the fibers felt sticky, and a cross (×) was used if they felt sticky.

[0058] [Table 2]

[0059] The present invention demonstrates that, compared to the case using the comparative copolymer (ratio A-1), the acid scavenger yields a resin composition that is colorless and free from bleed-out of the acid scavenger component. [Industrial applicability]

[0060] The acid scavenger of the present invention not only exhibits excellent acid scavenging performance but also has excellent dispersibility in resins containing chlorine atoms, so there is no deterioration in the appearance of the resin composition comprising the acid scavenger and the resin. For this reason, it can be suitably used as an acid scavenger for thermoplastic resins containing chlorine atoms that are subjected to heat processing.

Claims

1. An acid scavenger comprising a copolymer (A) having a glycidyl group (meth)acrylate and a radical polymerizable monomer represented by the following general formula (1) as essential constituent monomers. 【Chemistry 1】 [In general formula (1), A represents an oxygen atom or NH. B represents an alkylene group having 1 to 4 carbon atoms. R １ R represents a hydrogen atom or a methyl group. ２ , R ３ and R ４ Each of these independently represents an alkyl group having 1 to 4 carbon atoms. － [This represents a halogen ion.]

2. A resin composition comprising a copolymer (P) having vinyl chloride as an essential constituent monomer and at least one functional group selected from the group consisting of a sulfonic acid (salt) group, a carboxylic acid (salt) group, and a phosphoric acid (salt) group, and the acid scavenger described in claim 1.

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