Chloroprene polymer latex composition, and adhesive composition

Abstract

To provide a chloroprene polymer latex composition capable of obtaining an adhesive composition excellent in initial adhesive strength right after bonding an adherend, and an adhesive composition including the same.SOLUTION: A chloroprene polymer latex composition includes a chloroprene polymer where a moving distance of an adherend measured at 23°C and humidity of 50% in accordance with the following tackiness evaluation test is less than 80 mm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a chloroprene polymer latex composition and an adhesive composition. [Background technology]

[0002] Adhesives containing chloroprene polymers are used in solvent-based contact adhesives and graft adhesives because they can provide high adhesion to a variety of substrates with low pressure. However, solvent-based adhesives are flammable and toxic, and regulations are becoming stricter every year. Therefore, water-based adhesives using chloroprene polymer latex are being developed.

[0003] For example, Patent Document 1 discloses a chloroprene polymer latex containing an emulsifier which is an alkali metal salt of a carboxylic acid and 0.1 to 0.5 parts by weight of a polyoxyalkylene derivative represented by a specific formula per 100 parts by weight of the chloroprene polymer latex, and an adhesive composition containing the chloroprene polymer latex. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-160295 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional adhesive compositions containing a chloroprene polymer latex composition have insufficient initial adhesive strength immediately after bonding adherends, and have sometimes resulted in misalignment between the adherends. The present invention has been made in view of these circumstances, and an object of the present invention is to provide a chloroprene polymer latex composition that can provide an adhesive composition that has excellent initial adhesive strength immediately after bonding adherends, and an adhesive composition containing the same. [Means for solving the problem]

[0006] According to the present invention, there is provided a chloroprene polymer latex composition containing a chloroprene polymer, which exhibits a movement distance of an adherend of less than 80 mm at 23°C and 50% humidity as measured based on the following tackiness evaluation test. <Tackiness evaluation test> 1. A composition for evaluating tackiness is prepared by adjusting the solid content of the chloroprene polymer latex composition to 55% by mass. 2. Prepare a table equipped with an inclined plate having an inclination angle of 35 degrees with respect to the horizontal. The composition for evaluating tackiness is applied to the entire surface of the canvas at a rate of 200 g / m 2 The canvas is then fixed with the coated surface facing up so as to cover the inclined plate. 3. Place an adherend made of stainless steel with a long side of 100 mm, a short side of 30 mm, and a thickness of 3 mm on top of the canvas on the inclined plate, so that the long side of the adherend is in the direction of the inclination of the inclined plate and one of the short sides of the adherend is aligned with the upper end of the canvas, without applying pressure to the adherend in a direction pressing it against the inclined plate. 4. One minute after placing the adherend, measure the distance traveled by the adherend in the inclined direction from the position where the adherend was placed.

[0007] The present inventors have conducted extensive research and have found that by controlling the amount of displacement of specific adherends in a tack evaluation test measured under specific conditions to fall within a specific numerical range, an adhesive composition can be obtained that exhibits excellent initial adhesive strength immediately after adhering the adherends, leading to the completion of the present invention.

[0008] Various embodiments of the present invention will be described below as examples, and the embodiments shown below can be combined with each other. [1] A chloroprene polymer latex composition containing a chloroprene polymer, wherein the movement distance of an adherend measured at 23°C and 50% humidity based on the following tackiness evaluation test is less than 80 mm. <Tackiness evaluation test> 1. A composition for evaluating tackiness is prepared by adjusting the solid content of the chloroprene polymer latex composition to 55% by mass. 2. Prepare a table equipped with an inclined plate having an inclination angle of 35 degrees with respect to the horizontal. The composition for evaluating tackiness is applied to the entire surface of the canvas at a rate of 200 g / m 2 The canvas is then fixed with the coated surface facing up so as to cover the inclined plate. 3. Place an adherend made of stainless steel with a long side of 100 mm, a short side of 30 mm, and a thickness of 3 mm on top of the canvas on the inclined plate, so that the long side of the adherend is in the direction of the inclination of the inclined plate and one of the short sides of the adherend is aligned with the upper end of the canvas, without applying pressure to the adherend in a direction pressing it against the inclined plate. 4. One minute after placing the adherend, measure the distance traveled by the adherend in the inclined direction from the position where the adherend was placed. [2] The chloroprene polymer latex composition according to [1], wherein the chloroprene polymer has a toluene-insoluble content of 30% by mass or less. [3] The chloroprene polymer latex composition according to [1] or [2], comprising 0.5 to 3.5 parts by mass of a conjugated resin acid per 100 parts by mass of the chloroprene polymer. [4] The chloroprene polymer latex composition according to any one of [1] to [3], wherein the content of the nonionic emulsifier per 100 parts by mass of the chloroprene polymer is 0.40 parts by mass or less. [5] The chloroprene polymer latex composition according to [4], wherein the nonionic emulsifier comprises at least one selected from polyoxyalkylene phenyl ether emulsifiers, polyoxyalkylene alkyl ether emulsifiers, polyoxyethylene sorbitan fatty acid ester emulsifiers, polyoxyethylene sorbitol fatty acid ester emulsifiers, sorbitan fatty acid ester emulsifiers, glycerin fatty acid ester emulsifiers, polyoxyethylene alkylamine emulsifiers, polyoxyethylene fatty acid ester emulsifiers, and alkyl alkanolamide emulsifiers. [6] The chloroprene polymer latex composition according to any one of [1] to [5], wherein the chloroprene polymer has an average particle size of 160 nm or less. [7] An adhesive composition comprising the chloroprene polymer latex composition according to any one of [1] to [6]. [8] The adhesive composition according to [7], further comprising a pH adjuster. [9] The adhesive composition according to [7] or [8], wherein the movement distance of the adherend measured based on the tackiness evaluation test at 23°C and 50% humidity is less than 80 mm.

[10] The adhesive composition according to any one of [7] to [9], which is for polyurethane foam. [Effects of the Invention]

[0009] The chloroprene polymer latex composition of the present invention can provide an adhesive composition that exhibits excellent initial adhesive strength immediately after bonding adherends, and can reduce slippage between adherends. The adhesive composition containing the chloroprene polymer latex composition of the present invention exhibits excellent initial adhesive strength immediately after bonding adherends, and is less likely to cause slippage between adherends, reducing the occurrence of defects in the bonding process and improving quality. The adhesive composition containing the chloroprene polymer latex composition of the present invention can be suitably used as a spray-type adhesive for bonding, for example, polyolefin resins and foams, particularly polyurethane foams. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an outline of the tackiness evaluation test in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below by illustrating embodiments of the present invention. The present invention is not limited by these descriptions. The features of the embodiments of the present invention described below can be combined with each other. Furthermore, each feature can be an invention independently.

[0012] 1. Chloroprene polymer latex composition The chloroprene polymer latex composition according to the present invention contains a chloroprene polymer, and the movement distance of an adherend measured based on the tackiness evaluation test below at 23° C. and 50% humidity is less than 80 mm.

[0013] <Tackiness evaluation test> 1. A composition for evaluating tackiness is prepared by adjusting the solid content concentration of the chloroprene polymer latex composition to 55% by mass. 2. Prepare a table equipped with an inclined plate having an inclination angle of 35 degrees with respect to the horizontal. The composition for evaluating tackiness is applied to the entire surface of the canvas at a rate of 200 g / m 2The canvas is then fixed with the coated surface facing up so as to cover the inclined plate. 3. Place an adherend made of stainless steel with a long side of 100 mm, a short side of 30 mm, and a thickness of 3 mm on top of the canvas on the inclined plate, so that the long side of the adherend is in the direction of the inclination of the inclined plate and one of the short sides of the adherend is aligned with the upper end of the canvas, without applying pressure to the adherend in a direction pressing it against the inclined plate. 4. One minute after placing the adherend, measure the distance traveled by the adherend in the inclined direction from the position where the adherend was placed.

[0014] The tackiness evaluation test will be described in detail below with reference to FIGS. 1A to 1C. In step 1, a composition for evaluating tackiness is prepared by adjusting the solid content concentration of a chloroprene polymer latex composition to 55% by mass.

[0015] In step 2, a tilting table 1 is prepared, which includes a tilting plate 2 having a tilt angle of 35 degrees relative to the horizontal. A glass plate can be used as the tilting plate 2, and as an example, a glass plate measuring 400 mm x 400 mm and 4 mm thick can be used. Next, the composition for evaluating tackiness is applied to the entire surface of the canvas 3 at a rate of 200 g / m 2 The composition is applied to the canvas 3. Here, No. 9 cotton canvas can be used as the canvas 3, and as an example, a rectangular No. 9 cotton canvas with a long side of 300 mm and a short side of 90 mm can be used. The canvas 3 can be undyed and natural colored. The time from the start of application of the composition for tackiness evaluation to the completion of application can be 1 to 2 minutes, and can be 1 minute. Next, the canvas 3 is fixed on the inclined plate 2 with the coated side of the composition for tackiness evaluation facing up. At this time, the canvas 3 is fixed so that the short side (top end) of the canvas 3 is parallel to the top side (top edge) of the inclined plate 2. The canvas 3 can be fixed to the inclined table by using masking tape on both the left and right long sides of the canvas 3.

[0016] In step 3, an adherend 4 made of stainless steel (SUS) with a long side of 100 mm, a short side of 30 mm, and a thickness of 3 mm is placed on the coated surface of canvas 3 on the inclined plate 2 so that the long side of the adherend 4 faces the inclination direction of the inclined plate 2, one short side of the adherend 4 is aligned with the top edge of the canvas 3, and pressure is not applied to the adherend 4 in the direction pressing it against the inclined plate 2 (Figure 1A). The SUS used here can be SUS316L #400, which is polished with a #400 buff (#400). The adherend is preferably placed promptly after the application of the tackiness evaluation composition is completed; the time between the application of the tackiness evaluation composition and the placement of the adherend can be 30 seconds.

[0017] In step 4, one minute after the adherend 4 is placed, the distance traveled by the adherend 4 in the inclined direction from the position where the adherend 4 is placed is measured. Figure 1B shows an example of the movement of the adherend 4 one minute after the adherend 4 is placed. Figure 1C shows the movement distance (X).

[0018] The chloroprene polymer latex composition according to the present invention has a movement distance of an adherend measured in a tackiness evaluation test at 23°C and 50% humidity of less than 80 mm. The movement distance of an adherend measured in a tackiness evaluation test at 23°C and 50% humidity is, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, or 79 mm, and may be within a range between any two of the values ​​exemplified here.

[0019] By specifying the movement distance of the adherend measured based on a tack evaluation test for a chloroprene polymer latex composition, it is possible to improve the initial adhesive strength immediately after bonding the adhesive composition to the adherends, thereby reducing slippage between the adherends. The mechanism by which this can be achieved is unclear, but is presumed to be as follows: In conventional bonding processes using adhesive compositions containing a chloroprene polymer latex composition, slippage between the adherends may occur. Furthermore, the occurrence of slippage was not always correlated with conventional ball tack tests or adhesion tests. The inventors conducted extensive research and found that by optimizing test conditions, such as the material to which the chloroprene polymer latex composition is applied and the material and contact area of ​​the adherend relative to the applied surface, it is possible to detect slight differences in the tackiness of the chloroprene polymer latex composition, which are difficult to evaluate using conventional methods. They also found that by setting the movement distance evaluated by this specific method to a certain value or less, it is possible to improve the very initial adhesive strength and reduce the occurrence of slippage in bonding processes using adhesive compositions containing a chloroprene polymer latex composition. This finding led to the completion of the present invention. The migration distance evaluated by the specific method according to the present invention is considered to be capable of detecting slight differences in tackiness of the chloroprene polymer latex composition, particularly, differences in initial tackiness. The migration distance evaluated by the specific method according to the present invention varies by adjusting the production conditions of the chloroprene polymer latex composition, and by changing the composition (type and amount of emulsifier), molecular weight distribution of the chloroprene polymer, toluene-insoluble matter, average particle size, dispersion state, etc., and can be controlled by adjusting these.

[0020] 1.1 Chloroprene polymers and chloroprene polymer latexes In the present invention, the chloroprene polymer latex refers to a latex containing a chloroprene polymer. The chloroprene polymer refers to a polymer containing monomer units derived from 2-chloro-1,3-butadiene (hereinafter also referred to as a chloroprene monomer), and includes a homopolymer of the chloroprene monomer and a copolymer containing monomer units derived from the chloroprene monomer and another monomer copolymerizable with the chloroprene monomer. Examples of the other monomer include 1-chloro-1,3-butadiene, 2,3-dichloro-1,3-butadiene, butadiene, isoprene, styrene, acrylonitrile, acrylic acid and its esters, and methacrylic acid and its esters.

[0021] The chloroprene polymer latex composition according to one embodiment of the present invention preferably contains 60 to 100% by mass of chloroprene monomer units, based on 100% by mass of the chloroprene polymer contained in the chloroprene polymer latex composition. The content of the chloroprene monomer units is, for example, 60, 65, 70, 75, 80, 85, 90, 95, 99, or 100% by mass, and may be within a range between any two of the values ​​exemplified here.

[0022] The chloroprene polymer latex composition according to one embodiment of the present invention may contain one type of chloroprene polymer, or may contain two or more types of chloroprene polymers. The chloroprene polymer latex composition according to one embodiment of the present invention preferably contains a homopolymer of a chloroprene monomer. The chloroprene polymer latex composition according to one embodiment of the present invention preferably contains 60 to 100 mass% of the homopolymer of a chloroprene monomer in terms of solid content, relative to 100 mass% of the solid content of the chloroprene polymer latex contained in the chloroprene polymer latex composition. The content of the homopolymer of a chloroprene monomer is, for example, 60, 65, 70, 75, 80, 85, 90, 95, or 100 mass%, and may be within a range between any two of the values ​​exemplified here. By containing the homopolymer of a chloroprene monomer, the chloroprene polymer latex composition according to one embodiment of the present invention can further improve the contact property, heat-resistant adhesion, and initial bond strength of an adhesive composition containing the chloroprene polymer latex composition.

[0023] <Toluene insolubles> The chloroprene polymer according to one embodiment of the present invention preferably has a toluene-insoluble content of 30% by mass or less, more preferably 10% by mass or less, and may have a toluene-insoluble content of, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30% by mass, or may be within a range between any two of the values ​​exemplified here. In the present invention, the toluene-insoluble content refers to the content of gel content in the chloroprene polymer that is insoluble in toluene. Furthermore, the sol refers to a component that is soluble in toluene. When the toluene-insoluble content (gel content) is within the above-mentioned range, the chloroprene polymer according to one embodiment of the present invention contains an appropriate amount of sol, which has excellent molecular mobility. Fusion of the molecular chains of the chloroprene polymer at the adhesive interface occurs quickly, tackiness is quickly developed, and the migration distance in the tackiness evaluation test according to the present invention is likely to fall within a specific range. This is thought to improve the initial adhesive strength when the adhesive composition is prepared, and to reduce the incidence of slippage.

[0024] The toluene-insoluble matter can be calculated by the following formula, where Ag is the mass of the chloroprene polymer obtained by freeze-drying the chloroprene polymer latex, and Bg is the gel content (insoluble matter) separated from a mixture obtained by dissolving the freeze-dried latex in toluene. Specifically, the toluene-insoluble matter can be calculated by the method described in the examples. Toluene insolubles (gel content) = B / A x 100 (%)

[0025] The toluene-insoluble content can be controlled by adjusting the polymerization conditions during production of the chloroprene polymer latex, for example, the types and amounts of the polymerization initiator and chain transfer agent, as well as production conditions such as the polymerization temperature, polymerization time, and polymerization rate.

[0026] When the chloroprene polymer latex composition contains two or more chloroprene polymers, the toluene-insoluble content of the mixture of the two or more chloroprene polymers is preferably within the above-mentioned range.

[0027] <Average particle size> The chloroprene polymer latex composition according to one embodiment of the present invention preferably has an average particle size of 160 nm or less, for example, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, or 160 nm, or may be within a range between any two of the values ​​exemplified here.

[0028] The average particle size of the chloroprene polymer latex composition can be determined by the cumulant method using an autocorrelation function determined by a photon correlation method in a dynamic light scattering method. Specifically, it can be determined by the method described in the Examples. The average particle size of the chloroprene polymer latex composition can be controlled by adjusting the polymerization conditions during the production of the chloroprene polymer latex, such as the type and amount of an emulsifier, the polymerization temperature, the polymerization time, the polymerization rate, and other production conditions.

[0029] 1.2 Conjugated resin acids The chloroprene polymer latex composition according to one embodiment of the present invention may contain 3.5 parts by mass or less, preferably 0.5 to 3.5 parts by mass, and more preferably 1.4 to 3.0 parts by mass of a conjugated resin acid relative to 100 parts by mass of the chloroprene polymer. The content of the conjugated resin acid relative to 100 parts by mass of the chloroprene polymer is, for example, 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, or 3.5 parts by mass, or may be within a range between any two of the values ​​exemplified here. The chloroprene polymer latex composition according to one embodiment of the present invention may not contain any conjugated resin acid.

[0030] The chloroprene polymer latex composition according to one embodiment of the present invention may contain 0.5 to 6.0 parts by mass of a non-conjugated resin acid relative to 100 parts by mass of the chloroprene polymer, and the content of the non-conjugated resin acid relative to 100 parts by mass of the chloroprene polymer may be, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2 , 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0 parts by mass, and may be within a range between any two of the numerical values ​​exemplified here.

[0031] In the chloroprene polymer latex composition according to one embodiment of the present invention, when the total content of the conjugated resin acid and the non-conjugated resin acid in the chloroprene polymer latex composition is taken as 100% by mass, the content of the conjugated resin acid can be 5% by mass or more. The content of the conjugated resin acid may be, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 90, or 100% by mass, or may be within a range between any two of the values ​​exemplified here.

[0032] Conjugated resin acids refer to resin acids (rosin acids) that have conjugated double bonds. Examples of conjugated resin acids include abietic acid, neoabietic acid, palustric acid, and levopimaric acid. The conjugated resin acids preferably include at least one of abietic acid and palustric acid, and more preferably include abietic acid. Examples of non-conjugated resin acids include dehydroabietic acid, pimaric acid, isopimaric acid, dihydroabietic acid, dihydropimaric acid, secodehydroabietic acid, deisopropyldehydroabietic acid, and demethyldehydroabietic acid.

[0033] The conjugated resin acids contained in the chloroprene polymer latex composition also include conjugated resin acids present in the form of conjugated resin acid salts. In the polymerization of chloroprene polymers, rosin acids (including conjugated resin acids and non-conjugated resin acids), conjugated resin acids, and non-conjugated resin acids can also be added in the form of rosin acid salts, conjugated resin acid salts, and non-conjugated resin acid salts. Furthermore, emulsion polymerization methods using rosin acids and the like are often carried out under strong alkaline conditions, and in strongly alkaline chloroprene polymer latexes, rosin acids, conjugated resin acids, and non-conjugated resin acids often exist in the form of salts. Examples of salts include alkali metal salts, such as potassium salts and sodium salts. Examples of compounds that form salts with rosin acids, conjugated resin acids, and non-conjugated resin acids include potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate. Conjugated resinates include potassium abietate, potassium neoabietate, potassium palustrine, and potassium levopimarate, as well as sodium abietate, sodium neoabietate, sodium palustrine, and sodium levopimarate.

[0034] The content of conjugated resin acid can be calculated by extracting the solid content of chloroprene polymer obtained by freeze-drying a chloroprene polymer latex with an ethanol / toluene azeotropic mixture (ETA solution) specified in JIS K 6229, treating the extract with hydrochloric acid, performing gas chromatography on the extract, determining the peak areas of the conjugated resin acid component and the non-conjugated resin acid component from the gas chromatography measurement results, and calculating the content of the conjugated resin acid component and the non-conjugated resin acid component relative to the total peak area. Specifically, it can be calculated by the method described in the Examples.

[0035] The content of the conjugated resin acid in the chloroprene polymer latex composition can be controlled by adjusting the type and amount of an emulsifier to be blended in the chloroprene polymer latex composition, particularly the type and amount of a rosin acid to be used in emulsion polymerization of the chloroprene polymer.

[0036] It is known that rosin acid or an alkali metal salt thereof is used as an emulsifier in the emulsion polymerization of chloroprene polymers. However, when a rosin acid containing a conjugated resin acid having a conjugated double bond is used as the rosin acid, polymerization may be inhibited. Furthermore, the stability or adhesive properties of the resulting chloroprene polymer latex may be insufficient. From this perspective, disproportionated rosin acid, particularly a disproportionated rosin alkali metal salt, may be used as an emulsifier in the emulsion polymerization of chloroprene polymers (especially for use in adhesives). In one embodiment of the present invention, an emulsifier containing a conjugated resin acid can be used in emulsion polymerization of a chloroprene polymer. By using an emulsifier containing a conjugated resin acid, the tackiness of the resulting chloroprene polymer latex composition can be more easily adjusted to an appropriate range.

[0037] The chloroprene polymer latex composition according to one embodiment of the present invention may contain a rosin acid having a conjugated resin acid content of 5% by mass or more. The conjugated resin acid content in the rosin acid may be, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 90, or 100% by mass, or may be within a range between any two of the values ​​exemplified here.

[0038] 1.3 Nonionic emulsifiers In the chloroprene polymer latex composition according to one embodiment of the present invention, the content of the nonionic emulsifier per 100 parts by mass of the chloroprene polymer is preferably 0.40 parts by mass or less, and more preferably 0.30 parts by mass or less. The content of the nonionic emulsifier may be, for example, 0, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, or 0.40 parts by mass, or may be within a range between any two of the values ​​exemplified herein. The chloroprene polymer latex composition according to one embodiment of the present invention may be free of a nonionic emulsifier. By including a nonionic emulsifier within the above-described range, the tackiness of the resulting chloroprene polymer latex composition can be more easily adjusted to an appropriate range. The content of the nonionic emulsifier per 100 parts by mass of the chloroprene polymer can be determined by the method described in the Examples.

[0039] The nonionic emulsifier preferably contains at least one selected from polyoxyalkylene phenyl ether emulsifiers, polyoxyalkylene alkyl ether emulsifiers, polyoxyethylene sorbitan fatty acid ester emulsifiers, polyoxyethylene sorbitol fatty acid ester emulsifiers, sorbitan fatty acid ester emulsifiers, glycerin fatty acid ester emulsifiers, polyoxyethylene alkylamine emulsifiers, polyoxyethylene fatty acid ester emulsifiers, and alkyl alkanolamide emulsifiers. The nonionic emulsifier preferably contains at least one of polyoxyalkylene phenyl ether emulsifiers and polyoxyalkylene alkyl ether emulsifiers, more preferably at least one of polyoxyethylene phenyl ether emulsifiers and polyoxyethylene alkyl ether emulsifiers, and more preferably a polyoxyethylene styryl phenyl ether emulsifier.

[0040] Polyoxyalkylene alkyl ether and polyoxyalkylene phenyl ether emulsifiers are RO(EO) n (PO) mIn the formula, R represents a linear or branched alkyl group having 8 to 30 carbon atoms or an unsubstituted or substituted phenyl group, preferably a linear or branched alkyl group having 8 to 12 carbon atoms or an unsubstituted or substituted phenyl group, and more preferably a styrenated phenyl group in which a hydrogen atom of the phenyl group is substituted with a styryl group, CH—CH(CH)—. EO represents an ethylene oxide group, and PO represents an alkylene oxide group having 3 or more carbon atoms, such as a propylene oxide group or a butylene oxide group, and the arrangement thereof may be block or random. Furthermore, n and m each represent a value of 0 to 100, preferably 0 to 50. Note that n+m>0.

[0041] The chloroprene polymer latex composition according to one embodiment of the present invention may contain an emulsifier or dispersant other than the conjugated resin acid, a salt thereof, the rosin acid, a salt thereof, and the nonionic emulsifier. The other emulsifiers and dispersants will be described later in the description of the production method of the chloroprene polymer latex.

[0042] 1.4 Characteristics of chloroprene polymer latex compositions The chloroprene polymer latex composition according to one embodiment of the present invention is a test adhesive composition containing 25 parts by mass of an acrylic emulsion (acrylic latex containing an acrylic polymer) and 11 parts by mass of a pH adjuster per 100 parts by mass of the chloroprene polymer latex composition, and the initial adhesive strength measured by the following method is 2.1 N / cm 2 It is preferable that this is equal to or greater than this.

[0043] The initial adhesive strength is, for example, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0 N / cm 2 and may be in a range between any two of the values ​​given here.

[0044] <Initial adhesive strength measurement method> Density 30kg / m 3 Two pieces of urethane foam (thickness 20 mm x length 50 mm x width 50 mm) were used as the adherends, and the adhesive was applied at 70 g / m in an atmosphere of 23°C. 2 The adhesive is sprayed onto each adherend so that the adhesive becomes uniform. After application, while the adhesive is still wet, the adhesive surfaces of the urethane foam are overlapped, and the 40 mm thick adherends (laminate) are compressed to 20 mm and held for 10 seconds. After leaving it in a 23°C atmosphere for 30 seconds, a tensile test is immediately performed in the direction perpendicular to the adhesive surface using a tensile tester (A&D Tensilon; tensile speed 200 mm / min) to measure the adhesive strength.

[0045] 2. Method for producing chloroprene polymer, chloroprene polymer latex, and chloroprene polymer latex composition The method for producing the chloroprene polymer latex according to the present invention is not particularly limited, and it can be produced by the following method. The method for producing the chloroprene polymer latex according to one embodiment of the present invention can include an emulsion polymerization step. In the emulsion polymerization step, raw material monomers including a chloroprene monomer or a chloroprene monomer and other monomers copolymerizable therewith are emulsion-polymerized using an emulsifier, a dispersant, a polymerization initiator, a chain transfer agent, a reducing agent, etc., as appropriate. When a target polymerization rate is reached, a polymerization terminator is added to obtain a chloroprene polymer latex. Furthermore, additives such as a nonionic emulsifier can be added to the chloroprene polymer latex obtained in this manner, as necessary. Furthermore, unreacted monomers may be removed by a concentration method such as vacuum distillation.

[0046] (emulsifier) The emulsifier preferably contains a conjugated resin acid. The amount of conjugated resin acid added can be 0 to 3.5 parts by mass relative to 100 parts by mass of all monomers used. The amount of conjugated resin acid added relative to 100 parts by mass of all monomers used is, for example, 0, 0.5, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, or 3.5 parts by mass, or may be within a range between any two of the values ​​exemplified here. The types of conjugated resin acids are as described above, and conjugated resin acids also include conjugated resin acids present in the form of conjugated resin acid salts.

[0047] The emulsifier may also contain a non-conjugated resin acid. The amount of non-conjugated resin acid added may be 0.5 to 6.0 parts by mass relative to 100 parts by mass of all the monomers used. The amount of non-conjugated resin acid added relative to 100 parts by mass of all the monomers used may be, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 3.10, 3.11, 3.12, 3.13, 3.14, 3.15, 3.16, 3.17, 3.18, 3.19, 3.20, 3.21, 3.22, 3.23, 3.24, 3.25, 3.26, 3.27, 3.28, 3.29, 3.30, 3.31, 3.32, 3.33, 3.34, 3.35, 3.36, 3.37, 3.38, 3.39, 3.40, 3.41, 3.42, 3.43, 3.44, 3.45, 3.46, 3.47, 3.48, 3.49, 3. 0.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0 parts by mass, and may be within a range between any two of the values ​​exemplified herein.

[0048] When the total content of conjugated resin acid and non-conjugated resin acid in the emulsifier is taken as 100% by mass, the content of conjugated resin acid can be 5% by mass or more, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 90, or 100% by mass, or may be within a range between any two of the values ​​exemplified here.

[0049] Generally, the disproportionated rosin acid used in emulsion polymerization of a chloroprene-based polymer is obtained by disproportionating raw rosin acid, and the disproportionated rosin acid has an extremely low content of conjugated resin acids or does not contain any conjugated resin acids. In one embodiment of the present invention, a rosin acid that has not been subjected to disproportionation treatment, such as raw rosin acid from tall rosin, gum rosin, or wood rosin, or a rosin acid that has not been subjected to a treatment to completely modify the conjugated resin acids to non-conjugated resin acids (including cases where some have been modified to non-conjugated resin acids and some remain as conjugated resin acids), can be used as an emulsifier.

[0050] The amount of rosin acid added may be 3.0 to 7.0 parts by mass per 100 parts by mass of all monomers used, although there are no particular limitations as long as the content of the conjugated resin acid in the resulting chloroprene polymer latex composition is within the above-mentioned range. The amount of rosin acid added may be, for example, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, or 7.0 parts by mass, or may be within a range between any two of the values ​​exemplified here.

[0051] The emulsifier may contain a rosin acid having a conjugated resin acid content of 5% by mass or more. The conjugated resin acid content in the rosin acid may be, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 90, or 100% by mass, or may be within a range between any two of the values ​​exemplified here.

[0052] The emulsifier used in the emulsion polymerization step can also contain rosin acid, including disproportionated rosin acid, and / or its alkali metal salt. When the emulsifier contains raw rosin acid and / or its salt, and disproportionated rosin acid and / or its salt, the emulsifier preferably contains 15% by mass or more of raw rosin acid and / or its salt, based on 100% by mass of the total of these rosin acids. The emulsifier may contain, for example, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 parts by mass of raw rosin acid and / or its salt, based on 100% by mass of the total of rosin acids, and may also be within a range between any two of the values ​​exemplified herein. As the emulsifier, emulsifiers and dispersants other than rosin acid and / or its alkali metal salts can also be used. Examples of emulsifiers and dispersants other than rosin acid and / or its alkali metal salts include cationic, anionic, and nonionic emulsifiers and dispersants. In one embodiment of the present invention, the emulsifier used in the emulsion polymerization process can include an emulsifier containing a conjugated resin acid and an anionic emulsifier or dispersant. To stabilize the chloroprene polymer latex when a pH adjuster is added, it is preferable to use an anionic emulsifier or dispersant such as a sulfate or sulfonate in combination with the anionic emulsifier or dispersant. Specific examples include alkyl sulfonates having 8 to 20 carbon atoms, alkyl aryl sulfates, condensates of sodium naphthalene sulfonate and formaldehyde, and sodium alkyl diphenyl ether disulfonate. The amount of the anionic emulsifier or dispersant added can be 0.05 to 5 parts by mass per 100 parts by mass of the total monomers used. The amount of emulsifier or dispersant other than rosin acid and / or its alkali metal salt added is, for example, 0.05, 0.1, 0.2, 0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0 parts by mass relative to 100 parts by mass of all monomers used, and may be within a range between any two of the numerical values ​​exemplified here.

[0053] (chain transfer agent) In the emulsion polymerization step, it is preferable to add a chain transfer agent to adjust the molecular weight, molecular weight distribution, and toluene-insoluble content of the chloroprene-based polymer. The chain transfer agent may be added at the initial stage of polymerization or during polymerization. Preferred chain transfer agents are long-chain alkyl mercaptans such as n-dodecyl mercaptan and t-dodecyl mercaptan, and dialkyl xanthogen disulfides such as diisopropyl xanthogen disulfide and diethyl xanthogen disulfide. Long-chain alkyl mercaptans are more preferred because they facilitate control of the molecular weight and toluene-insoluble content. The chain transfer agent can be used alone or in combination of two or more. The total amount of chain transfer agent added during emulsion polymerization is preferably 0.005 to 0.12 parts by mass per 100 parts by mass of the chloroprene monomer and the monomer copolymerizable with the chloroprene monomer. The total amount of chain transfer agent added is, for example, 0.005, 0.01, 0.05, 0.1, 0.11, or 0.12 parts by mass, and may be within a range between any two of the values ​​exemplified here.

[0054] (initiator) As the polymerization initiator, a conventional radical polymerization initiator can be used. Specifically, organic or inorganic peroxides such as benzoyl peroxide, potassium persulfate, and ammonium persulfate, and azo compounds such as azobisisobutyronitrile are used. In addition, a co-catalyst such as anthraquinone sulfonate, potassium sulfite, or sodium sulfite may be used in combination as appropriate.

[0055] (Potassium hydroxide and sodium hydroxide) In the emulsion polymerization step, sodium hydroxide and / or potassium hydroxide can be used in an amount of 0.01 to 2.0 parts by mass relative to 100 parts by mass of all the monomers used.

[0056] (reducing agent) In the emulsion polymerization step, a reducing agent can be added. Examples of the reducing agent include potassium pyrosulfite, potassium sulfite, potassium hydrogen sulfite, potassium phosphate, potassium hydrogen phosphate, sodium hydrogen sulfite, sodium sulfate, and thiourea dioxide. The amount of the reducing agent added can be 0.01 to 3.0 parts by mass per 100 parts by mass of the raw material monomers used in the polymerization step.

[0057] (polymerization conversion rate) The polymerization conversion rate of raw material monomers during emulsion polymerization of chloroprene polymers and the like is preferably 50% by mass or more but less than 90% by mass, more preferably 60 to 85% by mass. A polymerization conversion rate of 50% by mass or more reduces the solids concentration of the chloroprene polymer latex, which increases the load in the drying process after adhesive application and makes it difficult to uniformize the adhesive layer. It also prevents problems such as odor and deterioration of tack and adhesive strength due to residual chloroprene monomer. A polymerization conversion rate of less than 90% by mass prevents an increase in branching in the chloroprene polymer and an increase in molecular weight distribution due to an increase in molecular weight, thereby preventing a decrease in initial adhesive strength. The polymerization conversion rate (mass %) is calculated by [(total polymer mass / total monomer mass) × 100]. Hereinafter, the polymerization conversion rate may also be simply referred to as the polymerization rate.

[0058] (Polymerization temperature) Chloroprene polymers can be polymerized, for example, in the range of 0 to 45° C., and are preferably polymerized at a low temperature of 5 to 20° C. Polymerization at a low temperature of 5 to 20° C. further increases the proportion of trans-1,4 bonds in the polychloroprene molecule, further increasing the crystallization rate, and achieving more sufficient adhesive strength when made into an aqueous adhesive.

[0059] (polymerization terminator) In general, in the production of chloroprene polymers, a polymerization terminator is added to terminate the reaction when a predetermined polymerization rate is reached in order to obtain a polymer with the desired molecular weight and distribution. The polymerization terminator is not particularly limited, but examples thereof include phenothiazine, pt-butylcatechol, hydroquinone, hydroquinone monomethyl ether, and diethylhydroxylamine.

[0060] (nonionic emulsifier) The method for producing a chloroprene polymer latex according to one embodiment of the present invention may include a step of adding an emulsifier after polymerization termination. Examples of the emulsifier include nonionic emulsifiers. The types of nonionic emulsifiers are as described above. The amount of the nonionic emulsifier added is preferably 0.45 parts by mass or less relative to 100 parts by mass of the chloroprene polymer. The amount of the nonionic emulsifier added may be, for example, 0, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, or 0.45 parts by mass, and may be within a range between any two of the values ​​exemplified here. The method for producing a chloroprene polymer latex according to one embodiment of the present invention may not include a step of adding an emulsifier after polymerization termination. The emulsifier may be added at the beginning of polymerization, such as during charging, before adjusting the solids concentration, or after adjusting the solids concentration.

[0061] (solid content concentration) A method for producing a chloroprene polymer latex according to one embodiment of the present invention may include a step of removing unreacted monomers by a concentration method such as vacuum distillation. The solids concentration of the chloroprene polymer latex is not particularly limited, but can be adjusted to 40 to 65% by mass. The solids concentration of the chloroprene polymer latex is, for example, 40, 45, 50, 55, 60, or 65% by mass, and may be within a range between any two of the values ​​exemplified here. The solids concentration of the chloroprene polymer latex can be controlled by adjusting the blending ratio of a solvent such as water during emulsion polymerization of the chloroprene polymer, or by a concentration step such as vacuum distillation. The chloroprene polymer latex obtained by the above method can be used as it is or by adding an additive thereto to form a chloroprene polymer latex composition.

[0062] 3. Adhesive composition The adhesive composition according to the present invention can contain the above-mentioned chloroprene polymer latex composition.

[0063] 3.1 pH adjuster The adhesive composition according to one embodiment of the present invention may contain a pH adjuster. Addition of a pH adjuster can further improve initial adhesive strength and storage stability. A weak acid or a buffer solution can be used as the pH adjuster. Specifically, at least one compound selected from hydroxy acids such as citric acid and glycolic acid, boric acid, and amino acids is preferred, with amino acids being particularly preferred. Examples of amino acids include glycine, alanine, threonine, and proline, with glycine being more preferred in terms of cost, adhesive performance, ease of handling, and the like.

[0064] The adhesive composition according to one embodiment of the present invention preferably contains 1 to 20 parts by mass of a pH adjuster relative to 100 parts by mass of the solid content of the chloroprene polymer latex. The content of the pH adjuster is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts by mass, or may be within a range between any two of the values ​​exemplified here. One pH adjuster may be used alone, or two or more pH adjusters may be used in combination.

[0065] 3.2 Polymer emulsion The adhesive composition according to one embodiment of the present invention may contain a polymer emulsion (a latex containing a polymer other than a chloroprene-based polymer).

[0066] The polymer emulsion may be one or more selected from acrylic emulsion, urethane emulsion, styrene / butadiene rubber latex, acrylonitrile / butadiene rubber latex, natural rubber latex, etc., and preferably contains an acrylic emulsion. The acrylic emulsion can be obtained by (co)polymerizing a (meth)acrylic acid ester with a monomer that forms a functional group, a monomer that forms a crosslinking group, and / or another copolymerizable monomer, as needed.

[0067] In the adhesive composition according to one embodiment of the present invention, the content of the polymer emulsion relative to 100 parts by mass of the solids content of the chloroprene polymer latex is, for example, 0, 5, 10, 15, 20, 25, 30, 35, 40, or 45 parts by mass, and may be within a range between any two of the values ​​exemplified here. One type of polymer emulsion may be used alone, or two or more types may be used in combination. By including a polymer emulsion (particularly an acrylic emulsion, which is an acrylic latex containing an acrylic polymer), the adhesive composition according to one embodiment of the present invention can further improve its storage stability and the texture (hardness) of the adhesive layer while maintaining its initial adhesive strength.

[0068] The adhesive composition according to one embodiment of the present invention may contain known components, such as a tackifier, an acid acceptor, an antioxidant, a filler, a pigment, a colorant, a wetting agent, an antifoaming agent, a thickener, etc. Examples of tackifiers include phenolic resins, terpene resins, rosin derivative resins, and petroleum hydrocarbons. In the adhesive composition according to one embodiment of the present invention, the amount of thickener per 100 parts by mass of the solids content of the chloroprene polymer latex composition can be, for example, 0, 1, 2, 3, 4, or 5 parts by mass, or can be within a range between any two of the numerical values ​​exemplified here.

[0069] In one embodiment of the adhesive composition, the movement distance of an adherend measured in accordance with the tack evaluation test at 23°C and 50% humidity is preferably less than 80 mm. The movement distance of an adherend measured in accordance with the tack evaluation test at 23°C and 50% humidity is, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, or 79 mm, and may be within a range between any two of the values ​​exemplified here.

[0070] The adhesive composition according to one embodiment of the present invention has an initial adhesive strength of 2.1 N / cm as measured by the following method. 2 The initial adhesive strength is preferably 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0 N / cm. 2 and may be in a range between any two of the values ​​given here.

[0071] <Initial adhesive strength measurement method> Density 30kg / m 3 Two pieces of urethane foam (thickness 20 mm x length 50 mm x width 50 mm) were used as the adherends, and the adhesive was applied at 70 g / m in an atmosphere of 23°C. 2 The adhesive is sprayed onto each adherend so that the adhesive becomes uniform. After application, while the adhesive is still wet, the adhesive surfaces of the urethane foam are overlapped, and the 40 mm thick adherends (laminate) are compressed to 20 mm and held for 10 seconds. After leaving it in a 23°C atmosphere for 30 seconds, a tensile test is immediately performed in the direction perpendicular to the adhesive surface using a tensile tester (A&D Tensilon; tensile speed 200 mm / min) to measure the adhesive strength.

[0072] The adhesive composition according to one embodiment of the present invention can be suitably used as an adhesive, preferably an aqueous adhesive, more preferably a one-component aqueous adhesive. The adhesive composition according to one embodiment of the present invention can be suitably used as a spray-type adhesive, and particularly as a spray-type adhesive for adhering the following adherends:

[0073] Adherends that can be bonded with the adhesive composition according to one embodiment of the present invention include foams made of materials such as polyurethane, ethylene-vinyl acetate copolymer, and polyethylene, as well as wood, cloth, and textiles. The adhesive composition according to one embodiment of the present invention can be used for polyurethane foams, and at least one of the adherends can be polyurethane foam. For example, the adhesive composition is suitable for bonding polyurethane foams to each other, polyurethane foam to wood, and polyurethane foam to cloth, and can be used effectively in bonding, for example, in the manufacture of furniture containing polyurethane foam components. [Example]

[0074] The present invention will be described in more detail below based on examples, but the present invention should not be construed as being limited to these examples.

[0075] <Preparation of chloroprene polymer latex A> A 10 L polymerization vessel was charged with 100 parts by weight of chloroprene (monomer), 0.1 parts by weight of n-dodecyl mercaptan, 90 parts by weight of purified water, 5.00 parts by weight of potassium rosinate A (containing conjugated resin acid, prepared in-house), 0.55 parts by weight of potassium hydroxide, 0.30 parts by weight of sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, Demol N), and 0.3 parts by weight of NaHSO. Potassium persulfate was added as a polymerization initiator, and thiourea dioxide was added as a reducing agent. Polymerization was carried out at a polymerization temperature of 10°C under a nitrogen stream. When the polymerization conversion rate reached 83% by weight, phenothiazine, a polymerization terminator, was added to terminate the polymerization, yielding a pre-distillation latex. 0.01 parts by mass of polyoxyethylene styrylphenyl ether (Noigen EA-137, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added as a nonionic emulsifier, and the pre-distillation latex was distilled under reduced pressure to remove unreacted monomers, thereby obtaining a post-distillation chloroprene polymer latex A (solid content: 55% by mass) containing a chloroprene polymer.

[0076] The above chloroprene polymer latexes A to F were used as chloroprene polymer latex compositions.

[0077] <Preparation of chloroprene polymer latexes B to F> Chloroprene polymer latexes B to F were obtained by the same procedure as for the chloroprene polymer latex A, except that the formulation and conditions were as shown in Table 1. Note that, as the disproportionated potassium rosinate, Longis K-25 manufactured by Arakawa Chemical Industries, Ltd. was used.

[0078] <Contents of conjugated resin acid components and non-conjugated resin acid components in rosin acid components> The contents of conjugated resin acid components and non-conjugated resin acid components in the potassium rosinate A were measured. First, rosin acid was dissolved in an ethanol / toluene azeotropic mixture (ETA solution) specified in JIS K 6229, and the solution was treated with hydrochloric acid to obtain a solution (rosin acid: 1.5% by mass). Gas chromatography was performed using this solution under the following conditions.

[0079] (Gas chromatography conditions) Gas chromatograph mass spectrometer: JEOL Jms-Q1050GC, manufactured by JEOL Ltd. Column used: FFAP 0.32mmφ×25m (film thickness 0.3μm) Column temperature: 200℃ (hold for 90 minutes) → 250℃ Heating rate: 10℃ / min ·Inlet temperature: 270℃ ·Injection volume: 1μL Interface temperature: 270℃ Ion source temperature: 270℃ Ionization current: 50μA Ionization voltage: 70eV Detector voltage: -1000V Ionization method: EI method

[0080] From the results of gas chromatography, the peak areas of the conjugated resin acid components, i.e., abietic acid (abietic acid and its salts; the same applies to other resin acids), neoabietic acid, palustric acid, and levopimaric acid, were determined, and the peak areas of the non-conjugated resin acid components, i.e., dehydroabietic acid, pimaric acid, isopimaric acid, and dihydroabietic acid, were determined. The area percentage of the peak area of ​​each component relative to the total peak area was considered to be the content of each component, and the contents of the conjugated resin acid components and non-conjugated resin acid components were measured.

[0081] In potassium rosinate A, the area percentages of the conjugated resin acids were 38.5% abietic acid, 1.2% neoabietic acid, 2.3% palustric acid, and 2.6% levopimaric acid, for a total area of ​​44.6%. The area percentages of the non-conjugated resin acids were 33.5% dehydroabietic acid, 8.0% pimaric acid, and 5.2% dihydroabietic acid, for a total area of ​​46.7%.

[0082] When the above-mentioned disproportionated potassium rosinate was similarly subjected to gas chromatography, no abietic acid component, neoabietic acid component, palustric acid component, or levopimaric acid component was detected, and the area percentages of the non-conjugated resin acid components were 68.8% for dehydroabietic acid, 0.5% for pimaric acid, and 21.1% for dihydroabietic acid, with the total area of ​​the non-conjugated resin acid components being 90.4%.

[0083] <Tackiness evaluation> The tackiness of the chloroprene polymer latex composition was evaluated according to the following procedure. 1 A composition for evaluating tackiness was prepared by adjusting the solid content concentration of the above-mentioned chloroprene polymer latex composition to 55% by mass. 2. A table was prepared with an inclined plate having an inclination angle of 35 degrees with respect to the horizontal. Here, a glass plate measuring 400 mm x 400 mm and 4 mm thick was used as the inclined plate. Next, the composition for evaluating tackiness was applied to the entire surface of the canvas at a concentration of 200 g / m 2 The composition was applied to the canvas with a thickness of 100 mm. The canvas used was a rectangular No. 9 cotton canvas with a long side of 300 mm and a short side of 90 mm. The canvas used was undyed and natural colored. The canvas was fixed on an inclined plate with masking tape (24 mm wide) with the coated side with the composition for tackiness evaluation facing up. The canvas was fixed so that the short side of the canvas was parallel to the upper side (the upper end side) of the inclined plate. 3. An adherend made of stainless steel (SUS) with a long side of 100 mm, a short side of 30 mm, and a thickness of 3 mm was placed on top of the canvas on the inclined plate, with the long side of the adherend facing the inclination direction of the inclined plate and one short side of the adherend aligned with the top edge of the canvas, without applying pressure to the adherend in the direction pressing it against the inclined plate. Here, SUS316L #400, which was polished with a #400 buff (#400), was used as the stainless steel. 4 One minute after the adherend was placed, the distance traveled by the adherend in the inclined direction from the position where the adherend was placed was measured. The results are shown in Table 1.

[0084] <Content of conjugated resin acid component in chloroprene polymer> Test specimens were obtained by cutting 3 g of the solid chloroprene polymer obtained by freeze-drying the chloroprene polymer latex into 2 mm squares. The test specimens were placed in a recovery flask equipped with a condenser, extracted with an ethanol / toluene azeotropic mixture (ETA solution) as specified in JIS K 6229, and then treated with hydrochloric acid. The extract obtained was subjected to gas chromatography under the same conditions as described above for the analysis of the conjugated resin acid and non-conjugated resin acid contents in the rosin acid component, and the conjugated resin acid content in the chloroprene polymer was calculated. The results are shown in Table 1.

[0085] <Polyoxyethylene styryl phenyl ether content per 100 parts by mass of chloroprene polymer> The sample solution was prepared by dissolving 1.0 mg of the internal standard sodium trimethylsilylpropionate-d4 (TSP-d4) and approximately 30 mg of polyoxyethylene styryl phenyl ether (Noigen EA-137, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) in 1.0 mL of heavy water. 1 The H-NMR spectrum was measured using a JNM-ECX-400 (400 MHz, FT type) manufactured by JEOL Ltd. When heavy water (4.65 ppm) was used as the reference substance for chemical shifts, the peak area I from -0.50 to 0.50 ppm derived from TSP-d4 was TSP , the peak area of ​​3.00 to 4.00 ppm derived from polyoxyethylene styryl phenyl ether I EA-137 The unknown quantity M EA-137 / H EA-137 where W is mass, M is molecular weight, I is signal integral value, and H is the number of signal Hs. W TSP / M TSP :W EA-137 / M EA-137 =I TSP / H TSP :I EA-137 / H EA-137 The solid content obtained by freeze-drying the chloroprene polymer latex composition was extracted with an ethanol / toluene azeotropic mixture (ETA solution) specified in JIS K 6229, and the solid content was removed by filtration to obtain a solution, followed by removing the solvent to obtain a dry product. The ratio of the amount of the obtained dry product to the mass of the solid content of the chloroprene polymer latex composition was defined as the ETA extraction rate. The sample solution was prepared by dissolving approximately 30 mg of the above dried product and 1.0 mg of TSP-d4 in 1.0 mL of heavy water. 1 H-NMR spectra were measured using a JNM-ECX-400 (400 MHz, FT type) manufactured by JEOL Ltd. When heavy water (4.65 ppm) was used as the reference substance for chemical shifts, the peak area I from -0.50 to 0.50 ppm derived from TSP was TSP , the peak area of ​​3.00 to 4.00 ppm derived from polyoxyethylene styryl phenyl ether I x The mass of polyoxyethylene styryl phenyl ether contained in the sample solution, W, was obtained from the following relational expression: x was calculated. W TSP / M TSP :W x / M EA-137 =I TSP / H TSP :I x / H EA-137 The ratio C of the mass of polyoxyethylene styryl phenyl ether to the mass of the solid content of the chloroprene polymer latex composition was calculated by the following formula. C(%)=W x (mg) / mass of dried product (mg) x 100 x ETA extraction rate (%) From the obtained value of C, the parts by mass of polyoxyethylene styryl phenyl ether relative to 100 parts by mass of the chloroprene polymer was calculated, and the values ​​shown in Table 1 were obtained.

[0086] [Nuclear magnetic resonance analysis (1H-NMR) measurement conditions] Measurement mode: Non-decoupling Flip angle: 45 degrees Wait time: 4.3 seconds Sample rotation speed: 12Hz Windowing: Exponential Accumulation count: 32 Measurement temperature: 30°C

[0087] <Toluene insolubles> A test piece was obtained by cutting 1 g of the chloroprene polymer obtained by freeze-drying the above-mentioned chloroprene polymer latex composition into 2 mm squares. The test piece was placed in a conical beaker and dissolved in 80 g of toluene for 16 hours. Subsequently, after centrifugation, the gel fraction (insoluble matter) was separated using a 200-mesh wire netting. The gel fraction was then dried and the mass of the dried product was measured. The toluene-insoluble matter in the chloroprene polymer was calculated using the following formula, where Ag is the chloroprene polymer after freeze-drying and B g is the gel fraction (insoluble matter) separated from the mixture dissolved in toluene. Toluene insolubles (gel content) = B / A x 100 (%) The results are shown in Table 1.

[0088] <Average particle size> The chloroprene polymer latex composition was diluted with distilled water to a solid content of 0.01% by mass, and the average particle size was measured using an ELSZ Series (manufactured by Otsuka Electronics Co., Ltd.). The average particle size of the latex was determined by the cumulant method using the autocorrelation function obtained by the photon correlation method in dynamic light scattering. The results are shown in Table 1.

[0089] <Preparation of Water-Based Adhesive> To 100 parts by mass of the solid content of the chloroprene polymer latex obtained above, 25 parts by mass of acrylic emulsion (trade name "Acronal Proof 1299", BASF) and 11 parts by mass of glycine as a pH adjuster were added, and the mixture was stirred using a three-one motor to prepare an aqueous adhesive. The initial adhesive strength of the obtained aqueous adhesive was measured by the following method, and the measurement results are shown in Table 1.

[0090] [Initial adhesive strength] Density 30kg / m 3Two pieces of urethane foam (thickness 20 mm x length 50 mm x width 50 mm) were used as the adherends, and the adhesive was applied at 70 g / m in an atmosphere of 23°C. 2 The adhesive was sprayed onto each adherend so that the adhesive was applied to the adhesive surface. After application, while the adhesive was still wet, the adhesive surfaces of the urethane foam were placed together, and the 40 mm thick adherend (laminate) was compressed to 20 mm and held for 10 seconds. After leaving it in a 23°C atmosphere for 30 seconds, a tensile test was immediately performed in the direction perpendicular to the adhesive surface using a tensile tester (A&D Tensilon; tensile speed 200 mm / min) to measure the adhesive strength.

[0091] [Table 1] [Explanation of symbols]

[0092] 1 ramp 2 Inclined plate 3 Canvas 4 Adherent X Travel distance

Claims

1. A chloroprene polymer latex composition containing a chloroprene polymer, A chloroprene polymer latex composition, which, when measured at 23°C and 50% humidity based on the following tackiness evaluation test, exhibits a movement distance of an adherend of less than 80 mm. <Tackiness evaluation test> 1. A composition for evaluating tackiness is prepared by adjusting the solid content of the chloroprene polymer latex composition to 55% by mass.

2. Prepare a table equipped with an inclined plate having an inclination angle of 35 degrees with respect to the horizontal. The composition for tackiness evaluation was applied to the entire surface of the canvas at a rate of 200 g / m2. ２ The canvas is then fixed with the coated surface facing up so as to cover the inclined plate.

3. Place an adherend made of SUS with a long side of 100 mm, a short side of 30 mm, and a thickness of 3 mm on top of the canvas on the inclined plate, so that the long side of the adherend is in the direction of the inclination of the inclined plate and one of the short sides of the adherend is aligned with the upper end of the canvas, without applying pressure to the adherend in a direction pressing it against the inclined plate.

4. One minute after placing the adherend, the distance traveled by the adherend in the inclined direction from the position where the adherend was placed is measured.

2. The chloroprene polymer latex composition according to claim 1, The chloroprene polymer latex composition, wherein the toluene-insoluble content of the chloroprene polymer is 30% by mass or less.

3. The chloroprene polymer latex composition according to claim 1 or claim 2, The chloroprene polymer latex composition contains 0.5 to 3.5 parts by mass of a conjugated resin acid relative to 100 parts by mass of the chloroprene polymer.

4. The chloroprene polymer latex composition according to claim 1 or claim 2, The chloroprene polymer latex composition has a nonionic emulsifier content of 0.40 parts by mass or less based on 100 parts by mass of the chloroprene polymer.

5. The chloroprene polymer latex composition according to claim 4, The chloroprene polymer latex composition, wherein the nonionic emulsifier comprises at least one selected from the group consisting of polyoxyalkylene phenyl ether emulsifiers, polyoxyalkylene alkyl ether emulsifiers, polyoxyethylene sorbitan fatty acid ester emulsifiers, polyoxyethylene sorbitol fatty acid ester emulsifiers, sorbitan fatty acid ester emulsifiers, glycerin fatty acid ester emulsifiers, polyoxyethylene alkylamine emulsifiers, polyoxyethylene fatty acid ester emulsifiers, and alkyl alkanolamide emulsifiers.

6. The chloroprene polymer latex composition according to claim 1 or claim 2, The chloroprene polymer latex composition, wherein the chloroprene polymer has an average particle size of 160 nm or less.

7. An adhesive composition comprising the chloroprene polymer latex composition according to claim 1 or 2.

8. The adhesive composition of claim 7, further comprising a pH adjuster.

9. The adhesive composition according to claim 7, An adhesive composition in which the movement distance of an adherend measured based on the tackiness evaluation test at 23°C and 50% humidity is less than 80 mm.

10. The adhesive composition according to claim 7, which is for polyurethane foam.

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