PVC resin paste

Abstract

To provide a paste vinyl chloride resin that has excellent foaming printing sharpness for rotary screen printing wallpaper.SOLUTION: A paste vinyl chloride resin contains, relative to 100 pts.wt. of a vinyl chloride resin with an average degree of polymerization of 700-1500, 0.5-2 pts.wt. of alkylsulfate, and 0.05-0.5 pts.wt. of alkylbenzenesulfonate. When measured by the following condition 1, the average particle size is 2-100 μm, a particle component with a particle size of 0.01-5 μm is 20-60 vol.%, and a particle component with a particle size of 5-200 μm is 40-80 vol.%. The condition 1: 100 pts.wt. of the paste vinyl chloride resin is blended with 60 pts.wt. of diisononyl phthalate, a sol of the paste vinyl chloride resin is prepared, and it is stored at 23°C for 2 hours before its particle size distribution is measured by laser diffraction scattering.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a vinyl chloride resin suitable for paste processing, and in particular to a paste vinyl chloride resin excellent for paste processing, which has a foamed printing layer with a sharp three-dimensional effect and has excellent properties for use in rotary screen printing wallpaper. [Background technology]

[0002] Paste vinyl chloride resins (hereinafter sometimes abbreviated as "paste PVC") are generally kneaded with plasticizers, fillers, stabilizers or other compounding agents to prepare paste vinyl vinyl sols, which are then used in a variety of molding processes to produce a variety of molded products such as wallpaper, carpet tiles and gloves.

[0003] Particularly in fields requiring design, such as wallpaper, various rotary screen printing methods using vinyl chloride paste resins have been investigated. However, these vinyl chloride paste resins and their compositions do not necessarily have fully satisfactory rotary printing properties, for example, they may be insufficient in terms of pattern shape retention, etc. For example, paste sol compositions for rotary screen printing have been proposed that are excellent in basic performance as a printing composition, such as leveling properties, sharpness of printed patterns, shape retention, and high-speed printability, at a specific shear viscosity (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 06-340836 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the proposal in Patent Document 1 proposes a paste sol composition of a vinyl chloride-based paste resin and a blending resin, and no consideration has been given to paste PVC for wallpaper, particularly for rotary screen printing wallpaper.

[0006] Therefore, the present invention aims to provide a paste vinyl chloride resin that, when used as a foamed printing layer, produces a sharp three-dimensional effect and exhibits excellent performance, particularly when used for rotary screen printing wallpaper. [Means for solving the problem]

[0007] As a result of extensive research into the above-mentioned problems, the present inventors have discovered that a paste vinyl chloride resin having specific properties and a specific formulation, when applied to foamed wallpaper as a paste vinyl vinyl sol, gives the foamed printed layer a sharp three-dimensional appearance and has excellent properties for use in rotary screen-printed wallpaper, thereby completing the present invention.

[0008] The present invention will be described in detail below.

[0009] The present invention relates to a vinyl chloride resin paste, characterized in that it contains 0.5 to 2 parts by weight of an alkyl sulfate and 0.05 to 0.5 parts by weight of an alkylbenzene sulfonate relative to 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 700 to 1500, and that when measured under the following condition 1, it has an average particle size of 2 to 100 μm, 20 to 60 vol% of particle components having particle sizes in the range of 0.01 to 5 μm, and 40 to 80 vol% of particle components having particle sizes in the range of 5 to 200 μm, and a method for producing the same. Condition 1: 60 parts by weight of diisononyl phthalate was mixed with 100 parts by weight of vinyl chloride resin paste to prepare a vinyl chloride resin paste sol. After storing at 23°C for 2 hours, the particle size distribution was measured using the laser diffraction / scattering method.

[0010] The vinyl chloride resin in the vinyl chloride resin paste of the present invention has an average degree of polymerization of 700 to 1500. In particular, since it provides excellent effects of matte finish and surface smoothness, it preferably has an average degree of polymerization of 900 to 1400, and more preferably 1000 to 1300. Here, if the average degree of polymerization is less than 700, the matte finish will be poor. On the other hand, if the degree of polymerization is more than 1500, the surface smoothness and foam sharpness will be poor. The average degree of polymerization of the vinyl chloride resin can be measured, for example, by calculating the degree of polymerization by solution viscosity measurement using an Ubbelohde viscometer according to JIS K6721.

[0011] The vinyl chloride resin paste of the present invention contains an alkylbenzene sulfonate, and the alkylbenzene sulfonate may be any salt that falls within the scope of the alkylbenzene sulfonate category, such as sodium dodecylbenzene sulfonate, potassium dodecylbenzene sulfonate, ammonium dodecylbenzene sulfonate, and triethanolammonium dodecylbenzene sulfonate. Of these, sodium dodecylbenzene sulfonate is preferred, as it results in a vinyl chloride resin paste with excellent surface smoothness.

[0012] The amount of alkylbenzene sulfonate to be added is 0.05 to 0.5 parts by weight per 100 parts by weight of vinyl chloride resin. In particular, 0.07 to 0.3 parts by weight is preferred, as this provides excellent surface smoothness, and 0.09 to 0.2 parts by weight is even more preferred. The alkylbenzene sulfonate may be an emulsifier used in obtaining the vinyl chloride resin, or it may be an emulsifier used in preparing the vinyl chloride resin, either as is or with the amount adjusted by adding or subtracting it separately. If the amount of alkylbenzene sulfonate is less than 0.05 parts by weight, the surface smoothness will be poor. On the other hand, if the amount exceeds 0.5 parts by weight, the foaming sharpness will be poor.

[0013] The vinyl chloride resin paste of the present invention contains an alkyl sulfate, and the alkyl sulfate may be any alkyl sulfate within the scope of the alkyl sulfate category. Among these, alkyl sulfates having a total carbon number of 10 to 14 are preferred. Examples of such alkyl sulfates include lauryl sulfates such as lithium lauryl sulfate, potassium lauryl sulfate, sodium lauryl sulfate, ammonium lauryl sulfate, and triethanolammonium lauryl sulfate; oleyl sulfates such as lithium oleyl sulfate, potassium oleyl sulfate, sodium oleyl sulfate, ammonium oleyl sulfate, and triethanolammonium oleyl sulfate; and myristyl sulfates such as lithium myristyl sulfate, potassium myristyl sulfate, sodium myristyl sulfate, ammonium myristyl sulfate, and triethanolammonium myristyl sulfate. Lauryl sulfates such as lithium lauryl sulfate, potassium lauryl sulfate, sodium lauryl sulfate, ammonium lauryl sulfate, and triethanolammonium lauryl sulfate are particularly preferred.

[0014] The amount of alkyl sulfate ester salt to be blended is 0.5 to 2 parts by weight per 100 parts by weight of vinyl chloride resin. In particular, 0.6 to 1.5 parts by weight is preferred, and 0.6 to 1 part by weight is even more preferred, as this provides excellent surface smoothness and foaming sharpness. The alkyl sulfate ester salt may be an emulsifier used in obtaining the vinyl chloride resin, or the amount of emulsifier used in preparing the vinyl chloride resin may be adjusted by adding or subtracting it separately. If the amount of alkyl sulfate ester salt is less than 0.5 parts by weight, the surface smoothness will be poor. On the other hand, if the amount exceeds 2 parts by weight, the surface smoothness and foaming sharpness will be poor.

[0015] The vinyl chloride paste resin of the present invention is prepared by blending 60 parts by weight of diisononyl phthalate as a plasticizer with 100 parts by weight of the vinyl chloride paste sol. After storing the paste at 23°C for 2 hours, the particle size distribution is measured by laser diffraction / scattering. The average particle size in the vinyl chloride paste sol is 2 to 100 μm, preferably 2 to 50 μm, and more preferably 3 to 20 μm. If the average particle size in the vinyl chloride paste sol is less than 2 μm, the sol viscosity increases over time, resulting in poor processability. On the other hand, if the average particle size is greater than 100 μm, clogging of the screen mesh occurs. Furthermore, the particle size distribution in the vinyl chloride paste sol is such that 20 to 60 vol% of the particle component has a particle size in the range of 0.01 to 5 μm (hereinafter sometimes referred to as component A) and 40 to 80 vol% of the particle component has a particle size in the range of 5 to 200 μm (hereinafter sometimes referred to as component B). If the content of component A or component B is outside these ranges, the foaming sharpness will be poor. When measuring the particle size distribution in the paste vinyl sol, any laser diffraction / scattering particle size distribution measuring device can be used as long as it is capable of measuring particle size distribution.

[0016] The vinyl chloride resin constituting the vinyl chloride resin paste of the present invention may be a vinyl chloride homopolymer or a copolymer, and examples of copolymerizable monomers in such copolymers include vinyl esters such as vinyl acetate, vinyl propionate, vinyl myristate, and vinyl benzoate; unsaturated carboxylic acids or anhydrides thereof such as acrylic acid, methacrylic acid, maleic acid, and fumaric acid; acrylic esters such as methyl acrylate, ethyl acrylate, and butyl acrylate; methacrylic esters such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate; unsaturated carboxylic esters such as maleic esters, fumaric esters, and cinnamic esters; vinyl ethers such as vinyl methyl ether, vinyl amyl ether, and vinyl phenyl ether; monoolefins such as ethylene, propylene, butene, and pentene; vinylidene chloride, styrene and its derivatives, acrylonitrile, and methacrylonitrile.

[0017] The vinyl chloride resin may be a vinyl chloride resin obtained by emulsion polymerization, microsuspension polymerization, seed emulsion polymerization, seed microsuspension polymerization, or the like, which are known as common polymerization methods for paste vinyl chloride resins. A vinyl chloride resin latex is obtained by these polymerization methods, and the resin or particles thereof can be obtained by removing water from the obtained latex. In this case, methods for removing water from the vinyl chloride resin latex include, for example, spray drying, fluidized bed drying, through-air drying, rotary drying, and conduction heating drying. Among these, spray drying is preferred because it can remove water efficiently.

[0018] As an example of the production of the vinyl chloride resin and vinyl chloride resin latex, a method using seed microsuspension polymerization will be described below.

[0019] The seed microsuspension polymerization method is a polymerization method comprising: 1) a first step of obtaining a vinyl chloride resin seed latex containing a vinyl chloride resin containing an oil-soluble polymerization initiator by microsuspension polymerization; and 2) a second step of polymerizing the obtained seed latex with vinyl chloride monomer, or vinyl chloride monomer and a monomer copolymerizable therewith, under gentle stirring in the presence of deionized water, an emulsifier, a buffer, and, if necessary, an emulsifying aid such as a higher alcohol, to enlarge the seed latex and obtain a vinyl chloride resin latex.

[0020] Examples of monomers copolymerizable with vinyl chloride monomer include the above-mentioned monomers. In addition to the alkylbenzenesulfonates and alkyl sulfates, the emulsifiers may be one or more of the following conventionally known emulsifiers: sulfosuccinates such as dioctyl sodium sulfosuccinate and dihexyl sodium sulfosuccinate; anionic emulsifiers such as polyoxyethylene alkyl sulfates and polyoxyethylene alkylaryl sulfates; sorbitan esters such as sorbitan monooleate and polyoxyethylene sorbitan monostearate; and nonionic emulsifiers such as polyoxyethylene alkylphenyl ethers and polyoxyethylene alkyl esters. Examples of buffers include alkali metal monohydrogen phosphates, alkali metal dihydrogen phosphates, potassium hydrogen phthalate, sodium bicarbonate, and boric acid-caustic potassium solution.

[0021] Furthermore, examples of emulsifying aids that may be used as needed include higher alcohols such as cetyl alcohol and lauryl alcohol; higher fatty acids such as lauric acid, palmitic acid and stearic acid, and esters thereof; aromatic hydrocarbons, higher fatty acid hydrocarbons, and halogenated hydrocarbons such as chlorinated paraffins.

[0022] Furthermore, a vinyl chloride resin seed latex used in a seed microsuspension polymerization method can be prepared by the following microsuspension polymerization method. First, vinyl chloride monomer, an oil-soluble polymerization initiator, a surfactant, a buffer, a higher alcohol, a higher fatty acid, a higher fatty acid ester, a dispersing aid such as chlorinated paraffin, and optionally a polymerization degree modifier are added to form a premix, and the mixture is homogenized using a homogenizer to adjust the oil droplets. Examples of homogenizers that can be used in this process include a colloid mill, a vibration mixer, and a two-stage high-pressure pump. The homogenized liquid is then sent to a polymerization vessel, and the temperature inside the polymerization vessel is raised while gently stirring to initiate the polymerization reaction. Polymerization is continued until a predetermined conversion rate is reached, thereby preparing a vinyl chloride resin seed latex containing an oil-soluble polymerization initiator.

[0023] In this case, the oil-soluble polymerization initiator is preferably a diacyl peroxide having a 10-hour half-life temperature of 30 to 70°C. Examples of such oil-soluble polymerization initiators include isobutyryl peroxide, 3,3,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, and succinic acid peroxide.

[0024] The vinyl chloride resin latex can then be spray-dried to produce a vinyl chloride resin paste, in the form of primary particles or aggregates thereof. The aggregate particles may also be pulverized as needed. A commonly used dryer may be used to produce the vinyl chloride resin paste, such as the various spray dryers shown in Figure 4.10 on page 121 of "SPRAY DRYING HANDBOOK" (K. Masters, 3rd Edition, 1979, published by George G. W. Limited). The drying air inlet and outlet temperatures are not particularly limited. In particular, a drying air inlet temperature of 160 to 230°C and a drying air outlet temperature of 60 to 70°C are preferred, as these methods allow for efficient production of vinyl chloride resin paste and provide excellent properties and foaming sharpness for rotary screen printing wallpaper.

[0025] The vinyl chloride paste resin of the present invention can be blended with plasticizers, fillers, pigments, foaming agents, diluents, stabilizers, etc. to form a paste vinyl sol with excellent moldability. This paste vinyl chloride resin can be used in a variety of applications, such as films, sheets, wallpaper, flooring, and foam sheets. It is particularly suitable for use in foam wallpaper, which requires surface smoothness, surface strength, foamability, etc., and is particularly suitable for use in rotary screen-printed wallpaper. [Effects of the Invention]

[0026] The vinyl chloride resin paste of the present invention can provide foams that have excellent surface smoothness and foam printing sharpness, and is suitable for foam wallpaper, particularly for rotary screen printing wallpaper, and is therefore of great industrial value. [Example]

[0027] The vinyl chloride resin pastes obtained in the examples were evaluated as follows.

[0028] <Degree of polymerization of vinyl chloride resin> The degree of polymerization was calculated by the solution viscosity measurement method using an Ubbelohde viscometer according to JIS K6721.

[0029] <Measurement of particle size distribution in paste vinyl sol> A paste vinyl sol was prepared by blending 60 parts by weight of diisononyl phthalate with 100 parts by weight of vinyl chloride resin paste and storing it at 23°C for 2 hours. The PIDS concentration was then adjusted to 40-50%, and the particle size distribution was measured and the average particle size was calculated using a laser diffraction / scattering particle size analyzer (product name LS13320, manufactured by Beckman Coulter, Inc.).

[0030] <Expansion ratio> The vinyl chloride resin paste obtained was treated as a foam and the viscosity was calculated using the following formula (1). Foaming ratio = (thickness of foam - thickness of base sheet) / thickness of base sheet (1) <Surface smoothness> The surface of the resulting foam was observed and evaluated. ○: The surface is smooth. ×: The surface is rough.

[0031] <Foaming sharpness> The embossability of the resulting foam was observed and evaluated. The evaluation criteria for embossability are shown below. ○: The angle between the convex and concave surfaces is 50 degrees or more and less than 90 degrees. ×: The angle between the convex and concave surfaces is less than 50 degrees or greater than 90 degrees.

[0032] Synthesis Example 1 1m 3 A stainless steel autoclave was charged with 360 kg of deionized water, 300 kg of vinyl chloride monomer, 5.7 kg of lauroyl peroxide, and 30 kg of a 15 wt% aqueous solution of sodium dodecylbenzenesulfonate, and the mixture was circulated using a homogenizer for 3 hours to homogenize it. The temperature of the reaction system was then raised to 45°C to initiate polymerization. After the pressure in the polymerization system had decreased, the unreacted vinyl chloride monomer was recovered, yielding a vinyl chloride resin seed latex (a) with a solids content of 35 wt%, an average particle size of 0.55 μm, and containing 2 wt% lauroyl peroxide relative to the vinyl chloride resin.

[0033] Synthesis Example 2 1m 3 A stainless steel autoclave was charged with 400 kg of deionized water, 350 kg of vinyl chloride monomer, 2 kg of a 16 wt% aqueous potassium laurate solution, and 5 kg of a 16 wt% aqueous sodium dodecylbenzenesulfonate solution, and the temperature of the reaction system was raised to 60°C to initiate polymerization. After the pressure in the polymerization system was reduced, the unreacted vinyl chloride monomer was recovered, yielding a vinyl chloride resin seed latex (b) with a solid content of 40 wt% and an average particle size of 0.15 μm.

[0034] Example 1 A 2.5 L stainless steel autoclave was charged with 610 g of deionized water, 730 g of vinyl chloride monomer, 15 g of a 5 wt % aqueous solution of sodium dodecylbenzenesulfonate, 4 parts by weight of seed latex (a) having an average particle size of 0.55 μm obtained in Synthesis Example 1 per 100 parts by weight of vinyl chloride monomer, and 5 parts by weight of seed latex (b) having an average particle size of 0.15 μm per 100 parts by weight of vinyl chloride monomer. The temperature of the reaction mixture was raised to 54°C to initiate polymerization. From the start of polymerization to the end of polymerization, 0.7 parts by weight of a 5 wt % aqueous solution of sodium lauryl sulfate per vinyl chloride monomer was continuously added. The polymerization was terminated when the polymerization pressure dropped from the saturated vapor pressure of vinyl chloride monomer at 54°C to 0.37 MPa, and unreacted vinyl chloride monomer was recovered to obtain a vinyl chloride resin latex.

[0035] 1 kg of the resulting vinyl chloride resin latex was spray-dried using a rotary disk spray dryer at a hot air temperature of 210°C and an outlet temperature of 65°C to obtain a vinyl chloride resin paste. The resulting vinyl chloride resin paste contained 0.1 parts by weight of sodium dodecylbenzenesulfonate and 0.8 parts by weight of sodium lauryl sulfate per 100 parts by weight of vinyl chloride resin. The degree of polymerization of the vinyl chloride resin was 1100, and 60 parts by weight of diisononyl phthalate was blended. The particle size distribution of the prepared paste vinyl chloride sol had an average particle size of 9.9 μm, with 40 vol% of particles in the 0.01 to 5 μm particle size range and 60 vol% of particles in the 5 to 200 μm particle size range.

[0036] 100 parts by weight of the obtained vinyl chloride paste resin were mixed with 50 parts by weight of diisononyl phthalate (J-Plus Corporation, Grade Industrial Grade) as a plasticizer, 40 parts by weight of calcium carbonate (Sankyo Seifun Co., Ltd., Grade 1) as a filler, 10 parts by weight of titanium oxide (Teikai Corporation, Product Name JR600A) as a pigment, 3 parts by weight of a foaming agent (Otsuka Chemical Co., Ltd., Product Name AZ Ultra 1050), 10 parts by weight of a diluent (JX Nippon Oil & Energy Corporation, Product Name N10), and 3 parts by weight of a stabilizer (Adeka Corporation, Product Name FL-103N), and the mixture was kneaded using a dissolver to obtain a vinyl chloride paste sol.

[0037] The obtained paste vinyl chloride sol was coated to a thickness of 0.14 mm on flame-retardant paper that had been preheated at 180°C for 5 seconds, and then heated at 190°C for 10 seconds to obtain a raw sheet.

[0038] The thickness of the obtained raw sheet was measured, and then heated at 210°C for 35 seconds to obtain a foam. The thickness of the obtained foam was then measured, and the expansion ratio, surface smoothness, and foaming sharpness were evaluated. The test results are shown in Table 1. The expansion ratio was 4.8 times, and the surface smoothness and foaming sharpness were excellent.

[0039] Example 2 A 2.5 L stainless steel autoclave was charged with 610 g of deionized water, 730 g of vinyl chloride monomer, 15 g of a 5 wt % aqueous solution of sodium dodecylbenzenesulfonate, 4 parts by weight of seed latex (a) having an average particle size of 0.55 μm obtained in Synthesis Example 1 per 100 parts by weight of vinyl chloride monomer, and 5 parts by weight of seed latex (b) having an average particle size of 0.15 μm per 100 parts by weight of vinyl chloride monomer. The temperature of the reaction mixture was raised to 54°C to initiate polymerization. From the start of polymerization to the end of polymerization, 0.7 parts by weight of a 5 wt % aqueous solution of sodium lauryl sulfate per vinyl chloride monomer was continuously added. The polymerization was terminated when the polymerization pressure dropped from the saturated vapor pressure of vinyl chloride monomer at 54°C to 0.37 MPa, and unreacted vinyl chloride monomer was recovered to obtain a vinyl chloride resin latex.

[0040] 1 kg of the resulting vinyl chloride resin latex was spray-dried using a rotary disk spray dryer at a hot air temperature of 190°C and an outlet temperature of 60°C to obtain a vinyl chloride resin paste. The resulting vinyl chloride resin paste contained 0.1 parts by weight of sodium dodecylbenzenesulfonate and 0.8 parts by weight of sodium lauryl sulfate per 100 parts by weight of vinyl chloride resin. The degree of polymerization of the vinyl chloride resin was 1100, and 60 parts by weight of diisononyl phthalate was blended. The paste vinyl chloride sol prepared had an average particle size of 5.0 μm, with 50 vol% of particles in the particle size range of 0.01 to 5 μm and 50 vol% of particles in the particle size range of 5 to 200 μm.

[0041] 100 parts by weight of the obtained vinyl chloride paste resin were mixed with 50 parts by weight of diisononyl phthalate (J-Plus Corporation, Grade Industrial Grade) as a plasticizer, 40 parts by weight of calcium carbonate (Sankyo Seifun Co., Ltd., Grade 1) as a filler, 10 parts by weight of titanium oxide (Teikai Corporation, Product Name JR600A) as a pigment, 3 parts by weight of a foaming agent (Otsuka Chemical Co., Ltd., Product Name AZ Ultra 1050), 10 parts by weight of a diluent (JX Nippon Oil & Energy Corporation, Product Name N10), and 3 parts by weight of a stabilizer (Adeka Corporation, Product Name FL-103N), and the mixture was kneaded using a dissolver to obtain a vinyl chloride paste sol.

[0042] The obtained paste vinyl chloride sol was coated to a thickness of 0.14 mm on flame-retardant paper that had been preheated at 180°C for 5 seconds, and then heated at 190°C for 10 seconds to obtain a raw sheet.

[0043] The thickness of the obtained raw sheet was measured, and then heated at 210°C for 35 seconds to obtain a foam. The thickness of the obtained foam was then measured, and the expansion ratio, surface smoothness, and foaming sharpness were evaluated. The test results are shown in Table 1. The expansion ratio was 4.7 times, and the surface smoothness and foaming sharpness were excellent.

[0044] Example 3 A 2.5 L stainless steel autoclave was charged with 500 g of deionized water, 800 g of vinyl chloride monomer, 15 g of a 5 wt % aqueous solution of sodium dodecylbenzenesulfonate, 4 parts by weight of seed latex (a) having an average particle size of 0.55 μm obtained in Synthesis Example 1 per 100 parts by weight of vinyl chloride monomer, and 5 parts by weight of seed latex (b) having an average particle size of 0.15 μm per 100 parts by weight of vinyl chloride monomer. The temperature of the reaction mixture was raised to 64°C to initiate polymerization. From the start of polymerization to the end of polymerization, 0.7 parts by weight of a 5 wt % aqueous solution of sodium lauryl sulfate per vinyl chloride monomer was continuously added. The polymerization was terminated when the polymerization pressure dropped from the saturated vapor pressure of vinyl chloride monomer at 64°C to 0.38 MPa, and unreacted vinyl chloride monomer was recovered to obtain a vinyl chloride resin latex.

[0045] 1 kg of the resulting vinyl chloride resin latex was spray-dried using a rotary disk spray dryer at a hot air temperature of 190°C and an outlet temperature of 60°C to obtain a vinyl chloride resin paste. The resulting vinyl chloride resin paste contained 0.1 parts by weight of sodium dodecylbenzenesulfonate and 0.8 parts by weight of sodium lauryl sulfate per 100 parts by weight of vinyl chloride resin. The degree of polymerization of the vinyl chloride resin was 850, and 60 parts by weight of diisononyl phthalate was blended. The particle size distribution of the prepared paste vinyl chloride sol had an average particle size of 3.0 μm, with 58 vol% of particles in the 0.01 to 5 μm particle size range and 42 vol% of particles in the 5 to 200 μm particle size range.

[0046] 100 parts by weight of the obtained vinyl chloride paste resin were mixed with 50 parts by weight of diisononyl phthalate (J-Plus Corporation, Grade Industrial Grade) as a plasticizer, 40 parts by weight of calcium carbonate (Sankyo Seifun Co., Ltd., Grade 1) as a filler, 10 parts by weight of titanium oxide (Teikai Corporation, Product Name JR600A) as a pigment, 3 parts by weight of a foaming agent (Otsuka Chemical Co., Ltd., Product Name AZ Ultra 1050), 10 parts by weight of a diluent (JX Nippon Oil & Energy Corporation, Product Name N10), and 3 parts by weight of a stabilizer (Adeka Corporation, Product Name FL-103N), and the mixture was kneaded using a dissolver to obtain a vinyl chloride paste sol.

[0047] The obtained paste vinyl chloride sol was coated to a thickness of 0.14 mm on flame-retardant paper that had been preheated at 180°C for 5 seconds, and then heated at 190°C for 10 seconds to obtain a raw sheet.

[0048] The thickness of the obtained raw sheet was measured, and then heated at 210°C for 35 seconds to obtain a foam. The thickness of the obtained foam was then measured, and the expansion ratio, surface smoothness, and foaming sharpness were evaluated. The test results are shown in Table 1. The expansion ratio was 4.4 times, and the surface smoothness and foaming sharpness were excellent.

[0049] [Table 1]

[0050] Comparative Example 1 A 2.5 L stainless steel autoclave was charged with 610 g of deionized water, 730 g of vinyl chloride monomer, 15 g of a 5 wt % aqueous solution of sodium dodecylbenzenesulfonate, 4 parts by weight of seed latex (a) having an average particle size of 0.55 μm obtained in Synthesis Example 1 per 100 parts by weight of vinyl chloride monomer, and 5 parts by weight of seed latex (b) having an average particle size of 0.15 μm per 100 parts by weight of vinyl chloride monomer. The temperature of the reaction mixture was raised to 54°C to initiate polymerization. From the start of polymerization to the end of polymerization, 0.7 parts by weight of a 5 wt % aqueous solution of sodium lauryl sulfate per vinyl chloride monomer was continuously added. The polymerization was terminated when the polymerization pressure dropped from the saturated vapor pressure of vinyl chloride monomer at 54°C to 0.37 MPa, and unreacted vinyl chloride monomer was recovered to obtain a vinyl chloride resin latex.

[0051] 1 kg of the resulting vinyl chloride resin latex was spray-dried using a rotary disk spray dryer at a hot air temperature of 160°C and an outlet temperature of 55°C to obtain a vinyl chloride resin paste. The resulting vinyl chloride resin paste contained 0.1 parts by weight of sodium dodecylbenzenesulfonate and 0.8 parts by weight of sodium lauryl sulfate per 100 parts by weight of vinyl chloride resin. The degree of polymerization of the vinyl chloride resin was 1100, and 60 parts by weight of diisononyl phthalate was blended. The particle size distribution of the prepared paste vinyl chloride sol had an average particle size of 1.9 μm, with 67 vol% of particles in the 0.01 to 5 μm particle size range and 33 vol% of particles in the 5 to 200 μm particle size range.

[0052] 100 parts by weight of the obtained vinyl chloride paste resin were mixed with 50 parts by weight of diisononyl phthalate (J-Plus Corporation, Grade Industrial Grade) as a plasticizer, 40 parts by weight of calcium carbonate (Sankyo Seifun Co., Ltd., Grade 1) as a filler, 10 parts by weight of titanium oxide (Teikai Corporation, Product Name JR600A) as a pigment, 3 parts by weight of a foaming agent (Otsuka Chemical Co., Ltd., Product Name AZ Ultra 1050), 10 parts by weight of a diluent (JX Nippon Oil & Energy Corporation, Product Name N10), and 3 parts by weight of a stabilizer (Adeka Corporation, Product Name FL-103N), and the mixture was kneaded using a dissolver to obtain a vinyl chloride paste sol.

[0053] The obtained paste vinyl chloride sol was coated to a thickness of 0.14 mm on flame-retardant paper that had been preheated at 180°C for 5 seconds, and then heated at 190°C for 10 seconds to obtain a raw sheet.

[0054] The thickness of the obtained raw sheet was measured, and then heated at 210°C for 35 seconds to obtain a foam. The thickness of the obtained foam was then measured, and the expansion ratio, surface smoothness, and foam sharpness were evaluated. The test results are shown in Table 2. The expansion ratio was 4.4 times, and although the surface smoothness was excellent, the foam sharpness was poor.

[0055] Comparative Example 2 A 2.5 L stainless steel autoclave was charged with 610 g of deionized water, 730 g of vinyl chloride monomer, 15 g of a 5 wt % aqueous solution of sodium dodecylbenzenesulfonate, 4 parts by weight of seed latex (a) having an average particle size of 0.55 μm obtained in Synthesis Example 1 per 100 parts by weight of vinyl chloride monomer, and 5 parts by weight of seed latex (b) having an average particle size of 0.15 μm per 100 parts by weight of vinyl chloride monomer. The temperature of the reaction mixture was raised to 54°C to initiate polymerization. From the start of polymerization to the end of polymerization, 0.7 parts by weight of a 5 wt % aqueous solution of sodium lauryl sulfate per vinyl chloride monomer was continuously added. The polymerization was terminated when the polymerization pressure dropped from the saturated vapor pressure of vinyl chloride monomer at 54°C to 0.37 MPa, and unreacted vinyl chloride monomer was recovered to obtain a vinyl chloride resin latex.

[0056] 1 kg of the resulting vinyl chloride resin latex was spray-dried using a rotary disk spray dryer at a hot air temperature of 110°C and an outlet temperature of 50°C to obtain a vinyl chloride resin paste. The resulting vinyl chloride resin paste contained 0.1 parts by weight of sodium dodecylbenzenesulfonate and 0.8 parts by weight of sodium lauryl sulfate per 100 parts by weight of vinyl chloride resin. The degree of polymerization of the vinyl chloride resin was 1100, and 60 parts by weight of diisononyl phthalate was blended. The particle size distribution of the prepared paste vinyl chloride sol had an average particle size of 1.3 μm, with 95 vol% of particles in the 0.01 to 5 μm particle size range and 5 vol% of particles in the 5 to 200 μm particle size range.

[0057] 100 parts by weight of the obtained vinyl chloride paste resin were mixed with 50 parts by weight of diisononyl phthalate (J-Plus Corporation, Grade Industrial Grade) as a plasticizer, 40 parts by weight of calcium carbonate (Sankyo Seifun Co., Ltd., Grade 1) as a filler, 10 parts by weight of titanium oxide (Teikai Corporation, Product Name JR600A) as a pigment, 3 parts by weight of a foaming agent (Otsuka Chemical Co., Ltd., Product Name AZ Ultra 1050), 10 parts by weight of a diluent (JX Nippon Oil & Energy Corporation, Product Name N10), and 3 parts by weight of a stabilizer (Adeka Corporation, Product Name FL-103N), and the mixture was kneaded using a dissolver to obtain a vinyl chloride paste sol.

[0058] The obtained paste vinyl chloride sol was coated to a thickness of 0.14 mm on flame-retardant paper that had been preheated at 180°C for 5 seconds, and then heated at 190°C for 10 seconds to obtain a raw sheet.

[0059] The thickness of the obtained raw sheet was measured, and then heated at 210°C for 35 seconds to obtain a foam. The thickness of the obtained foam was then measured, and the expansion ratio, surface smoothness, and foam sharpness were evaluated. The test results are shown in Table 2. The expansion ratio was 4.2 times, and the surface smoothness and foam sharpness were poor.

[0060] Comparative Example 3 A 2.5 L stainless steel autoclave was charged with 610 g of deionized water, 730 g of vinyl chloride monomer, 15 g of a 5 wt % aqueous solution of sodium dodecylbenzenesulfonate, 2 g of 2 wt % potassium persulfate, 4 parts by weight of seed latex (a) with an average particle size of 0.55 μm obtained in Synthesis Example 1 per 100 parts by weight of vinyl chloride monomer, and 7 parts by weight of seed latex (b) with an average particle size of 0.15 μm per 100 parts by weight of vinyl chloride monomer. The temperature of the reaction mixture was raised to 51°C to initiate polymerization. From the start of polymerization to the end of polymerization, 0.7 parts by weight of a 5 wt % aqueous solution of sodium dodecylbenzenesulfonate per vinyl chloride monomer was continuously added. The polymerization was terminated when the polymerization pressure dropped to 0.33 MPa from the saturated vapor pressure of vinyl chloride monomer at 51°C, and unreacted vinyl chloride monomer was recovered to obtain a vinyl chloride resin latex.

[0061] 1 kg of the resulting vinyl chloride resin latex was spray-dried using a rotary disk spray dryer at a hot air temperature of 160°C and an outlet temperature of 55°C to obtain a vinyl chloride resin paste. The resulting vinyl chloride resin paste contained 0.9 parts by weight of sodium dodecylbenzenesulfonate per 100 parts by weight of vinyl chloride resin. The degree of polymerization of the vinyl chloride resin was 1300, and 60 parts by weight of diisononyl phthalate was blended. The particle size distribution of the prepared paste vinyl chloride sol had an average particle size of 3.2 μm, with 55 vol% of particles in the 0.01 to 5 μm particle size range and 45 vol% of particles in the 5 to 200 μm particle size range.

[0062] 100 parts by weight of the obtained vinyl chloride paste resin were mixed with 50 parts by weight of diisononyl phthalate (J-Plus Corporation, Grade Industrial Grade) as a plasticizer, 40 parts by weight of calcium carbonate (Sankyo Seifun Co., Ltd., Grade 1) as a filler, 10 parts by weight of titanium oxide (Teikai Corporation, Product Name JR600A) as a pigment, 3 parts by weight of a foaming agent (Otsuka Chemical Co., Ltd., Product Name AZ Ultra 1050), 10 parts by weight of a diluent (JX Nippon Oil & Energy Corporation, Product Name N10), and 3 parts by weight of a stabilizer (Adeka Corporation, Product Name FL-103N), and the mixture was kneaded using a dissolver to obtain a vinyl chloride paste sol.

[0063] The obtained paste vinyl chloride sol was coated to a thickness of 0.14 mm on flame-retardant paper that had been preheated at 180°C for 5 seconds, and then heated at 190°C for 10 seconds to obtain a raw sheet.

[0064] The thickness of the obtained raw sheet was measured, and then heated at 210°C for 35 seconds to obtain a foam. The thickness of the obtained foam was then measured, and the expansion ratio, surface smoothness, and foam sharpness were evaluated. The test results are shown in Table 2. The expansion ratio was 4.9 times, and although the surface smoothness was excellent, the foam sharpness was poor.

[0065] [Table 2] [Industrial Applicability]

[0066] The vinyl chloride resin paste of the present invention can provide foams that are excellent in surface smoothness and foam printing sharpness, and is suitable for use as foam wallpaper, particularly for rotary screen printing wallpaper.

Claims

1. A vinyl chloride resin paste characterized by comprising 0.5 to 2 parts by weight of an alkyl sulfate and 0.05 to 0.5 parts by weight of an alkylbenzene sulfonate relative to 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 700 to 1500, and having an average particle size of 2 to 100 μm, 20 to 60 vol% of particle components having particle sizes in the range of 0.01 to 5 μm, and 40 to 80 vol% of particle components having particle sizes in the range of 5 to 200 μm, as measured under the following condition 1: Condition 1: 60 parts by weight of diisononyl phthalate was blended with 100 parts by weight of a vinyl chloride resin paste to prepare a vinyl chloride resin paste sol. After storing at 23°C for 2 hours, the particle size distribution was measured by a laser diffraction / scattering method.

2. 2. The vinyl chloride resin paste according to claim 1, wherein the alkyl sulfate is at least one alkyl sulfate selected from the group consisting of lithium lauryl sulfate, sodium lauryl sulfate, ammonium lauryl sulfate, and triethanolammonium lauryl sulfate, and the alkyl benzene sulfonate is sodium dodecyl benzene sulfonate.

3. 3. The vinyl chloride resin paste according to claim 1, which is for rotary screen printing wallpaper.

4. 4. The method for producing a vinyl chloride resin paste according to claim 1, wherein a vinyl chloride resin latex containing 0.5 to 2 parts by weight of an alkyl sulfate and 0.05 to 0.5 parts by weight of an alkylbenzene sulfonate per 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 700 to 1500 is dried in a spray dryer at an inlet temperature of 160 to 230°C and an outlet temperature of 60 to 70°C.

5. A rotary screen-printed wallpaper comprising at least the vinyl chloride resin paste according to any one of claims 1 to 3, a plasticizer, and a filler.

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