JP2003012811A - Matte paste vinyl chloride resin and paste composition comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a matte paste vinyl chloride resin and a paste composition comprising the same, which form a dense matte surface and are excellent in mechanical strength. SOLUTION: An outer layer of a vinyl chloride resin having a thickness of 0.025 to 0.25 μm is coated on vinyl chloride resin particles having an average particle diameter of 0.5 to 1.5 μm and containing a THF-insoluble gel content of 80% by weight or more. Matte paste vinyl chloride resin formed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a matte paste vinyl chloride resin and a paste composition comprising the same. More specifically, the surface of a molded article obtained is excellent in matteness and compactness, The present invention also relates to a matte paste vinyl chloride resin having excellent strength for surface protection and a paste composition comprising the same.

[0002]

2. Description of the Related Art A vinyl chloride resin for paste processing forms a plastisol by being dispersed in a liquid component containing a plasticizer as a main component together with a filler and other compounding agents. Paste processing is a processing method in which the plastisol is molded by a method such as coating molding, spray molding, dip molding, rotational molding, or slush molding, and then heated and melted to obtain the desired molded product. Due to its high degree of freedom, it still boasts strong demand.

The surface of the molded product obtained by the paste processing has a different required texture depending on the type of the product. Especially, in the cushion floor application of recent floor materials, the surface having a high matteness and a dense texture. Has come to be required.

As a technique for imparting a matt property to the surface of a paste-processed molded product, Japanese Patent Publication No. 63-058858 is available.
Japanese Patent Laid-Open Publication No. 2004-53242 discloses that a vinyl chloride resin for paste processing is added to tetrahydrofuran (hereinafter referred to as THF) in an amount of 5 to 80%.
A method of using a paste vinyl chloride resin containing the insoluble gel component is proposed. Further, from the viewpoint of satisfying both matteness and mechanical strength, JP-A-08-259761 and JP-A-11-029677 disclose that a THF-insoluble gel content is 30 to 60% with respect to a paste vinyl chloride resin. A vinyl chloride resin particle having a particle diameter of 0.1 to 0.4 μm and consisting only of a THF-soluble component, or a vinyl chloride monomer having a gelation initiation temperature of 90 ° C. or lower and a chloride having a monomer having an ester bond. A method has been proposed in which vinyl chloride resin particles for paste processing, which are vinyl copolymer resin particles, are mixed.

[0005]

However, the vinyl chloride resin for paste processing proposed in Japanese Examined Patent Publication No. 63-058858 has a high mattness when a resin having a high insoluble gel fraction is used. However, its surface is
The insoluble gel components were formed by the concavo-convex formed by agglomeration, and only a surface lacking a dense feeling was obtained. In addition, the mechanical strength was low because the insoluble gel component was poorly dispersed.

Further, the vinyl chloride resin for paste processing proposed in JP-A-08-259771 and JP-A-11-029677 has a resin processing temperature of 180 ° C.
Although it is effective at such low temperatures, 200 ° C that matches the actual processing conditions at the cushion floor manufacturing site.
Under the above high-temperature processing conditions, the matting level was insufficient as compared with the above-mentioned highly insoluble gel system due to the progress of melting, and the range of use was limited.

According to the recent floor material market, the texture of the surface of the floor material is shifting to the direction of demanding higher matteness, and among them, more dense and high quality surface is demanded. Accordingly, the present invention has an object to provide a paste vinyl chloride resin and a paste composition containing the same, which can meet the demands of the market.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific vinyl chloride resin particle is used as an inner core and a vinyl chloride resin having a specific thickness It has been found that the use of a matte paste vinyl chloride resin having a skin layer gives a molded article having a dense matte surface and improved mechanical strength characteristics, and has completed the present invention.

That is, according to the present invention, the THF-insoluble gel content is 80%.
A vinyl chloride resin particle having an average particle diameter of 0.5 to 1.5 μm, which is contained by weight% or more, as a core, and has a thickness of 0.025 to 0.2.
The present invention relates to a matte paste vinyl chloride resin having a skin layer of 5 μm of vinyl chloride resin and a paste composition comprising the same.

The present invention will be described in more detail below.

The matte paste vinyl chloride resin of the present invention comprises vinyl chloride resin particles having an average particle diameter of 0.5 to 1.5 μm and containing a THF-insoluble gel content of 80% by weight or more as an inner core, and a thickness of 0. An outer skin layer of vinyl chloride resin having a thickness of 0.025 to 0.25 μm is formed.

Vinyl chloride resin particles, which are the inner core, are
80% by weight or more of F insoluble gel, preferably 90% by weight
It contains the above and has an average particle size of 0.5 to 1.5 μm. Here, TH of vinyl chloride resin particles
When the F insoluble content is less than 80% by weight, the surface of a molded product obtained by subjecting the obtained paste vinyl chloride resin to a molding process has an increased glossiness and lacks matte properties. Further, when the average particle size is less than 0.5 μm, the average particle size is very small even when the particle size enlargement due to the outer skin layer formed thereafter is taken into consideration, and the viscosity when converted to plastisol. Is high and inferior in workability. On the other hand, the average particle size is 1.5
If it exceeds μm, the denseness of the unevenness on the surface of the molded product when the resulting paste vinyl chloride resin is subjected to molding processing is impaired.

As the method for measuring the average particle size in the present invention, any method can be used as long as the average particle size can be measured. As such a method, for example, dispersion latex is subjected to laser diffraction. / Using a scattering type particle size distribution measuring device (manufactured by Horiba, Ltd., trade name LA-700),
A method of measuring under the condition of a refractive index of 1.3 can be mentioned.

As a method for preparing vinyl chloride resin particles having an average particle diameter of 0.5 to 1.5 μm and containing 80% by weight or more of THF-insoluble gel as the inner core, a general paste vinyl chloride resin is used. Can be adjusted by a method for producing such a compound, and examples of such a method include vinyl chloride monomers such as vinyl chloride monomers, surfactants, auxiliary emulsifiers such as higher alcohols, and oil-soluble polymerization. A microsuspension polymerization method in which an initiator is mixed and finely dispersed in deionized water with a homogenizer or the like, and then polymerization is performed under gentle stirring; a seed containing an oil-soluble polymerization initiator is prepared by the microsuspension polymerization method, A seed suspension polymerization method in which vinyl chloride monomer such as vinyl chloride monomer and a necessary amount of surfactant are added to the seed for polymerization; particles obtained by emulsion polymerization method or micro suspension polymerization method are used as seeds. Examples include a seed emulsion polymerization method in which a vinyl chloride monomer such as a vinyl chloride monomer, a water-soluble polymerization initiator, and a surfactant in an appropriate amount are added to the seed for polymerization. it can.

Then, in order to make the THF insoluble content of the vinyl chloride resin particles used in the present invention 80% by weight or more,
At the time of the above polymerization, a polyfunctional monomer having two or more ethylenic double bonds in the molecule may be used together with the vinyl chloride-based monomer. Examples of the polyfunctional monomer having two or more ethylenic double bonds in the molecule include triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, ethylene glycol divinyl ether, ethylene glycol dimethacrylate, Examples thereof include ethylene glycol diacrylate, diallyl phthalate, vinyl methacrylate, and vinyl crotonate. These can be used alone or in combination of two or more.

The oil-soluble polymerization initiator used in the above-mentioned polymerization method is not particularly limited as long as it dissolves in a vinyl chloride monomer and has an appropriate half-life at the polymerization temperature for obtaining a paste vinyl chloride resin. There is no limitation, for example, diacyl peroxides such as 2,4-dichlorobenzoyl peroxide, decanoyl peroxide and lauroyl peroxide; peroxydicarbonates such as di-2-ethylhexyl peroxydicarbonate and diallyl peroxydicarbonate. Peroxyesters such as t-butylperoxybivalate and t-butylperoxyneodecanoate; organic peroxides such as acetylcyclohexylsulfonyl peroxide and disuccinic acid peroxide can be used. . As the water-soluble polymerization initiator, for example, potassium persulfate, hydrogen peroxide, ammonium persulfate, etc. can be used. These polymerization initiators may be used either individually or in combination of two or more, and the amount used varies depending on the polymerization temperature and the like, but is generally 0.001 to 1 part by weight based on the charged vinyl chloride monomer. It is preferably in the range of.

Further, as a surfactant used for polymerization in some cases, for example, alkyl sulfate ester salts such as sodium lauryl sulfate and sodium myristyl sulfate; alkyl sulfonates such as sodium dodecylbenzenesulfonate; ammonium laurate and stearyl. Fatty acid salts such as potassium acid; anionic surfactants such as sodium dioctyl sulfosuccinate, sulfosuccinates such as sodium dihexyl sulfosuccinate can be mainly used. Further, for the purpose of stabilizing the polymerization, polyoxyethylene sorbitan esters, polyoxyethylene alkyl ethers, nonionic surfactants such as polyoxyethylene alkylphenyl ethers, lauryl alcohol, myristyl alcohol, stearyl alcohol, etc. Higher alcohol 1
One kind or two or more kinds can be used in combination with the anionic surfactant. The amount used at that time varies depending on the charged amount of vinyl chloride-based monomer and the target particle size of the paste vinyl chloride-based resin, but is generally 0.05 to 5 parts by weight based on the charged vinyl chloride monomer. It is preferably in the range.

The matte paste vinyl chloride resin of the present invention has a thickness around vinyl chloride resin particles having an average particle diameter of 0.5 to 1.5 μm and containing 80% by weight or more of THF-insoluble gel as a core. By forming an outer skin layer of vinyl chloride resin having a thickness of 0.025 to 0.25 μm, it is possible to prevent the THF-insoluble gel components of the inner core from directly contacting each other and agglomerating during gelling and melting, thereby making it uniform. It is intended to realize a matte surface having dense irregularities dispersed in. Here, when the thickness of the outer skin layer is less than 0.025 μm, the protective effect of the vinyl chloride resin particles as the inner core is not sufficient, and the vinyl chloride resin particles at the time of melting agglomerate to give a glossy surface with a dense unevenness. The erased surface cannot be obtained. On the other hand, when the thickness of the outer skin layer is more than 0.25 μm, the outer skin layer that melts the unevenness formed by the vinyl chloride resin particles covers the surface and the surface is flattened, and the matte property is not achieved.

The thickness of the outer skin layer can be calculated from the difference between the average particle size of the vinyl chloride resin particles serving as the inner core and the average particle size of the matte paste vinyl chloride resin after forming the outer skin layer.

As a method for forming the outer skin layer in the vinyl chloride resin of the matte paste of the present invention, for example, an aqueous dispersion (polymerized latex) in which vinyl chloride resin particles serving as the inner core are prepared, and a vinyl chloride monomer are added. A method of additionally polymerizing can be mentioned. At this time, the vinyl chloride-based monomer to be added may be introduced into the polymerization system by batch addition, plural times divided addition or continuous addition. Further, the polymerization for forming the outer skin layer may be carried out immediately after the adjustment of the vinyl chloride resin particles to be the inner core, or once the polymerization is completed, the water-soluble polymerization initiator is added again. Alternatively, a predetermined amount of vinyl chloride-based monomer may be polymerized. Further, in the polymerization for forming the outer skin layer, it is preferable to use a vinyl chloride monomer and a copolymerizable monomer in combination in order to further improve the gelling meltability of the matte paste vinyl chloride resin, Examples of the monomer copolymerizable with the vinyl chloride monomer that improves the gelling meltability include vinyl acetate, carboxylic acid vinyl esters such as vinyl propionate; maleic acid, itaconic acid, methacrylic acid, Examples thereof include esters of unsaturated carboxylic acids such as acrylic acid. Other additives such as a polymerization initiator and a surfactant may be the same as those described in the method for polymerizing vinyl chloride resin particles as the inner core.

The matte paste vinyl chloride resin of the present invention can be used as a paste composition by blending a plasticizer and a stabilizer. In that case, if necessary, the average particle size is aimed at decreasing the viscosity. 20-60 μm blending resin and average degree of polymerization of 300 for strength improvement
You may mix | blend the super high polymerization degree vinyl chloride resin etc. of 0-5000. Then, the paste composition can give a molded body having a dense matte surface by heating and melting after molding.

The plasticizer used in the paste composition of the present invention is not particularly limited, and may be a plasticizer used in the processing of ordinary paste vinyl chloride resin.
For example, adipic acid plasticizers such as di-n-butyl adipate, di- (2-ethylhexyl) adipate and di-isodecyl adipate; dimethyl phthalate, diethyl phthalate, di- (2-ethylhexyl) phthalate, di-n-octyl Phthalates such as phthalate, dinonyl phthalate, dibenzyl phthalate, butyl benzyl phthalate; trimellitic acid plasticizers such as triisooctyl trimellitate and tri- (2-ethylhexyl) trimellitate; adipic acid polyesters, Examples include polyester plasticizers such as phthalic acid polyester, and these may be used alone or in combination of two or more.

The stabilizer is not particularly limited,
Any stabilizer that is used during the processing of ordinary paste vinyl chloride resin may be used, and examples include epoxy stabilizers, barium stabilizers, calcium stabilizers, tin stabilizers, zinc stabilizers, and composites of these. One kind or two or more kinds of stabilizers may be used in combination.

[0024]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Preparation Example 1 (Preparation of seed particles 1) 720 g of deionized water, 600 g of vinyl chloride monomer, 11.4 g of lauroyl peroxide and 15% by weight aqueous sodium dodecylbenzenesulfonate solution 60 in a 2.5 liter polymerization vessel.
g was charged, the polymerization solution was homogenized with a homomixer for 75 minutes, and then the temperature was raised to 45 ° C. to proceed with the polymerization. After the pressure was reduced, the unreacted vinyl chloride monomer was recovered to obtain seed particles containing 2% by weight of lauroyl peroxide and having an average polymerization degree of 1700 and an average particle size of 0.55 μm.

The matte paste vinyl chloride resin and molded products obtained in the examples were evaluated by the following methods.

-THF-insoluble gel content- Vinyl chloride resin particles were recovered from the obtained polymerized latex, 50 ml of tetrahydrofuran was added to 1 g of the sample, and the mixture was stirred at 60 ° C for 24 hours and then at 4000 rpm for 6 minutes.
The THF-insoluble matter was recovered by sedimentation by centrifugal force for 0 minutes and then vacuum-dried at 40 ° C. to obtain the weight of the THF-insoluble matter. The percentage of the value with respect to the sample weight was defined as the THF-insoluble gel content.

-Average Degree of Polymerization- Based on JIS K6720-2, it was calculated from the specific viscosity.

-Average Particle Size- The re-dispersed latex obtained by crushing the obtained polymerized latex or dried resin before drying with an ultrasonic homogenizer is used as a laser diffraction / scattering type particle size distribution measuring device (trade name, manufactured by Horiba, Ltd.). LA-700) was measured twice under the condition that the refractive index was 1.3, and the average value was taken as the average particle diameter.

-Matteness- Gross meter (Nippon Denshoku Industries Co., Ltd., trade name VGS
-300A) was used to measure the reflectance of light irradiated to the molded sheet at an incident angle of 60 °, and the reflectance was defined as matte.

The smaller the reflectance, the greater the degree of matting.

-Surface State- The surface of the produced sheet was observed under an optical microscope for a state of aggregation of the THF-insoluble gel component forming a convex portion on the surface at a magnification of 75 times.

-Tensile Strength- According to the plastic tensile test method defined in JIS K7113, a molded sheet used as a JIS-3 test piece is subjected to a tensile tester (manufactured by Orientic Co., trade name T).
(ENSIRON RTM-500) was used and the measurement was performed under the conditions of a pulling speed of 200 m / min.

Example 1 500 g of deionized water, 500 g of vinyl chloride monomer, 6 g of triallyl isocyanurate, 36 g of seed particles obtained in Preparation Example 1 in a 2.5 l polymerization vessel, 5% sodium alkylsulfosuccinate aqueous solution 10 g, 0.1% by weight
Charge 8 g of ferrous sulfate aqueous solution, and then add the polymerization reaction system to 4 g.
The temperature was raised to 5 ° C to start the polymerization reaction. From the start of the polymerization reaction to the end of the polymerization reaction 0.1 wt% ascorbic acid aqueous solution 8
0 g was continuously added, and further, 50 g of a 5% sodium alkylsulfosuccinate aqueous solution was continuously added from 1.5 hours to 6 hours after the initiation of the polymerization reaction. The polymerization reaction was stopped when the pressure inside the polymerization vessel dropped to 0.3 MPa, and unreacted vinyl chloride monomer was recovered to obtain a polymerized latex containing vinyl chloride resin particles.

The obtained vinyl chloride resin particles had an average particle size of 1.01 μm and a THF-insoluble gel content of 95% by weight.

Next, 300 g of vinyl chloride monomer, 6 g of 1% by weight aqueous potassium persulfate solution and 1 g of 0.1% by weight ferrous sulfate aqueous solution were added to the polymerized latex containing the vinyl chloride resin particles, and the temperature was raised to 40.degree. After setting, an additional polymerization reaction was started. From the start of the additional polymerization reaction to the end of the additional polymerization reaction, 40 g of a 0.1 wt% aqueous ascorbic acid solution was continuously added, and a 0.5% aqueous solution of sodium alkylsulfosuccinate from 0.5 hours to 2 hours after the initiation of the additional polymerization reaction. 30 g was added continuously. The pressure inside the polymerization vessel is 0.25
When the pressure dropped to MPa, the additional polymerization reaction was stopped, unreacted vinyl chloride monomer was recovered, and a paste vinyl chloride resin latex was obtained.

The average particle size of the paste vinyl chloride resin in the obtained paste vinyl chloride resin latex is 1.22 μm.
m, and the thickness of the outer skin layer formed by the additional polymerization was 0.105 μm.

Next, the paste vinyl chloride resin latex was dried by a rotary disk type spray dryer, and the paste vinyl chloride resin was recovered through a pulverizer.

With respect to 60 parts by weight of the obtained paste vinyl chloride resin, 40 parts by weight of blending resin (manufactured by VITEC Co., Ltd., trade name 75BX), 50 parts by weight of di- (2-ethylhexyl) phthalate, and barium-zinc stabilizer ( Asahi Denka Kogyo Co., Ltd., trade name AC319) 3 parts by weight and epoxidized soybean oil 2 parts by weight are kneaded in a dissolver mixer and then degassed under reduced pressure at 2 × 10 ³ Pa or less for 30 minutes to form a paste composition. Prepared.

The obtained paste composition was thinly applied on a polyester film with a doctor knife and heated in a small oven (Matisse) at 220 ° C. for 1 minute to form a sheet having a thickness of 0.35 mm. After that, the sheet was peeled off from the polyester film and subjected to tests for matting property, surface condition and tensile strength. The evaluation results are shown in Table 1.
Shown in. The result of surface observation with an optical microscope is shown in FIG.

The obtained sheet had a very high mattness with a reflectance of 11.2%, and formed a highly dense surface with no surface roughness. As a result of observing the surface with an optical microscope, it was observed that the THF-insoluble gel component forming irregularities was finely dispersed. The tensile strength was 147 kg / cm ² .

Example 2 500 g of deionized water, 500 g of vinyl chloride monomer, 6 g of triallyl isocyanurate, 36 g of seed particles obtained in Preparation Example 1 in a 2.5 l polymerization vessel, 5% aqueous solution of sodium alkylsulfosuccinate 10 g, 0.1% by weight
Charge 8 g of ferrous sulfate aqueous solution, and then add the polymerization reaction system to 4 g.
The temperature was raised to 5 ° C to start the polymerization reaction. From the start of the polymerization reaction to the end of the polymerization reaction 0.1 wt% ascorbic acid aqueous solution 8
0 g was continuously added, and further, 50 g of a 5% sodium alkylsulfosuccinate aqueous solution was continuously added from 1.5 hours to 6 hours after the initiation of the polymerization reaction. The polymerization reaction was stopped when the pressure inside the polymerization vessel dropped to 0.3 MPa, and unreacted vinyl chloride monomer was recovered to obtain a polymerized latex containing vinyl chloride resin particles.

The vinyl chloride resin particles obtained had an average particle size of 1.01 μm and a THF-insoluble gel content of 95% by weight.

Next, 300 g of vinyl chloride monomer, 6 g of 1% by weight aqueous potassium persulfate solution and 1 g of 0.1% by weight ferrous sulfate aqueous solution were added to the polymerized latex containing the vinyl chloride resin particles, and the temperature was raised to 54 ° C. After setting, an additional polymerization reaction was started. 0.5% to 2 hours after the start of the additional polymerization reaction 5% aqueous solution of sodium alkylsulfosuccinate 3
0 g was added continuously. The pressure inside the polymerizer is 0.42M
When the pressure was reduced to Pa, the additional polymerization reaction was stopped, unreacted vinyl chloride monomer was recovered, and a paste vinyl chloride resin latex was obtained.

The obtained paste vinyl chloride resin had an average particle size of 1.19 μm, and the outer skin layer formed by additional polymerization had a thickness of 0.09 μm.

Next, the paste vinyl chloride resin latex was dried by a rotary disk type spray dryer, and the paste vinyl chloride resin was recovered through a pulverizer.

The obtained paste vinyl chloride resin was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1. In addition, Figure 2 shows the results of surface observation using an optical microscope.
Shown in.

The sheet thus obtained had a very high matte property with a reflectance of 11.6% and formed a highly dense surface with no roughness on the surface. As a result of observing the surface with an optical microscope, it was observed that the THF-insoluble gel component forming irregularities was finely dispersed. Tensile strength is 1
It was 36 kg / cm ² .

Example 3 In a 2.5-liter polymerization vessel, 500 g of deionized water, 600 g of vinyl chloride monomer, 6 g of triallyl isocyanurate, 30 g of seed particles obtained in Preparation Example 1 and 5% aqueous solution of sodium alkylsulfosuccinate were used. 12 g, 0.1% by weight
Charge 8 g of ferrous sulfate aqueous solution, and then add the polymerization reaction system to 4 g.
The temperature was raised to 5 ° C to start the polymerization reaction. From the start of the polymerization reaction to the end of the polymerization reaction 0.1 wt% ascorbic acid aqueous solution 8
0 g was continuously added, and further 60 g of a 5% sodium alkylsulfosuccinate aqueous solution was continuously added from 1.5 hours to 6 hours after the initiation of the polymerization reaction. The polymerization reaction was stopped when the pressure inside the polymerization vessel dropped to 0.3 MPa, and unreacted vinyl chloride monomer was recovered to obtain a polymerized latex containing vinyl chloride resin particles.

The vinyl chloride resin particles obtained had an average particle size of 1.05 μm and a THF-insoluble gel content of 93% by weight.

Then, 200 g of vinyl chloride monomer, 4 g of 1% by weight aqueous potassium persulfate solution and 1 g of 0.1% by weight aqueous ferrous sulfate solution were added to the polymerized latex containing the vinyl chloride resin particles, and the temperature was raised to 40.degree. After setting, an additional polymerization reaction was started. From the start of the additional polymerization reaction to the end of the additional polymerization reaction, 40 g of a 0.1 wt% ascorbic acid aqueous solution was continuously added, and further 0.5 hours after the start of the additional polymerization reaction, 2
Until the lapse of time, 20 g of a 5% sodium alkylsulfosuccinate aqueous solution was continuously added. The pressure in the polymerization vessel is 0.2
When the pressure dropped to 5 MPa, the additional polymerization reaction was stopped, unreacted vinyl chloride monomer was recovered, and a paste vinyl chloride resin latex was obtained.

The obtained paste vinyl chloride resin had an average particle size of 1.17 μm, and the outer skin layer formed by additional polymerization had a thickness of 0.06 μm.

Next, the paste vinyl chloride resin latex was dried by a rotary disk type spray dryer, and the paste vinyl chloride resin was recovered through a pulverizer.

The obtained paste vinyl chloride resin was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1. In addition, the result of surface observation with an optical microscope is shown in FIG.
Shown in.

The obtained sheet had a very high matte property with a reflectance of 10.3%, and formed a highly dense surface with no roughness on the surface. As a result of observing the surface with an optical microscope, it was observed that the THF-insoluble matter forming irregularities was finely dispersed. The tensile strength was 141 kg / cm ² .

Example 4 500 g of deionized water, 500 g of vinyl chloride monomer, 6 g of triallyl isocyanurate and 36 g of seed particles obtained in Preparation Example 1 were placed in a 2.5-liter polymerization vessel, and a 5% sodium alkylsulfosuccinate aqueous solution was prepared. 10 g, 0.1% by weight
8 g of a ferrous sulfate aqueous solution was charged, and then the temperature was raised to 45 ° C. to start the polymerization reaction. From the start of the polymerization reaction to the end of the polymerization reaction, 80 g of a 0.1 wt% ascorbic acid aqueous solution was continuously added, and further 50 g of a 5% sodium alkylsulfosuccinate aqueous solution was added from 1.5 hours to 6 hours after the initiation of the polymerization reaction. It is added continuously and the pressure in the polymerization vessel is 0.3.
The polymerization reaction is continued until the pressure drops to MPa, and the average particle size is 1.
It is 01 μm and the THF-insoluble gel content is 95% by weight. When a polymerized latex containing vinyl chloride resin particles was prepared, 300 g of vinyl chloride monomer was placed in the polymerization vessel and 1% by weight
6 g of potassium persulfate aqueous solution and 1 g of 0.1 wt% ferrous sulfate aqueous solution were added, and the temperature was set to 40 ° C. to start the additional polymerization reaction. From the start of the additional polymerization reaction to the end of the additional polymerization reaction, 40 g of a 0.1 wt% aqueous ascorbic acid solution was continuously added, and further, 5% sodium alkylsulfosuccinate from 0.5 hours to 2 hours after the initiation of the additional polymerization reaction. 30 g of aqueous solution were added continuously. The pressure in the polymerization vessel is 0.
When the pressure dropped to 25 MPa, the additional polymerization reaction was stopped, unreacted vinyl chloride monomer was recovered, and a paste vinyl chloride resin latex was obtained.

The obtained paste vinyl chloride resin had an average particle size of 1.28 μm, and the outer skin layer formed by additional polymerization had a thickness of 0.135 μm.

Next, the paste vinyl chloride resin latex was dried by a rotary disk type spray dryer and the paste vinyl chloride resin was recovered through a pulverizer.

The obtained paste vinyl chloride resin was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1. In addition, FIG. 4 shows the result of surface observation with an optical microscope.
Shown in.

The sheet thus obtained had a very high mattness with a reflectance of 10.1%, and formed a highly dense surface with no surface roughness. As a result of observing the surface with an optical microscope, it was observed that the THF-insoluble gel component forming irregularities was finely dispersed. The tensile strength was 152 kg / cm ² .

Comparative Example 1 500 g of deionized water, 500 g of vinyl chloride monomer, 6 g of triallyl isocyanurate, 36 g of seed particles obtained in Preparation Example 1 in a 2.5 l polymerization vessel, 5% aqueous solution of sodium alkylsulfosuccinate 10 g, 0.1% by weight
8 g of a ferrous sulfate aqueous solution was charged, and then the temperature was raised to 45 ° C. to start the polymerization reaction. From the start of the polymerization reaction to the end of the polymerization reaction, 80 g of a 0.1 wt% ascorbic acid aqueous solution was continuously added, and further 50 g of a 5% sodium alkylsulfosuccinate aqueous solution was added from 1.5 hours to 6 hours after the initiation of the polymerization reaction. Added continuously. The pressure in the polymerization vessel is 0.
The polymerization reaction was stopped when the pressure was lowered to 3 MPa, and unreacted vinyl chloride monomer was recovered to obtain a polymerized latex containing vinyl chloride resin particles.

The obtained vinyl chloride resin particles had an average particle size of 1.01 μm and a THF-insoluble gel content of 95% by weight.

Then, the polymerized latex containing the vinyl chloride resin particles was dried by a rotary disk type spray dryer and collected as a paste vinyl chloride resin through a pulverizer.

The obtained paste vinyl chloride resin was evaluated in the same manner as in Example 1.

The evaluation results are shown in Table 1. Further, the results of observing the surface with an optical microscope are shown in FIG.

The obtained sheet had a very high matte property with a reflectance of 8.1%, but the surface thereof had a rough texture and a highly dense surface. As a result of observing the surface with an optical microscope, it was observed that the THF-insoluble gel component forming irregularities was agglomerated. The tensile strength is 1
It was as low as 12 kg / cm ² .

Comparative Example 2 500 g of deionized water, 200 g of vinyl chloride monomer, 2 g of triallyl isocyanurate, 36 g of seed particles obtained in Preparation Example 1 in a 2.5-liter polymerization vessel, 5% aqueous solution of sodium alkylsulfosuccinate 4 g and 0.1 g of a 0.1 wt% ferrous sulfate aqueous solution were charged, and then the temperature was raised to 45 ° C. to start the polymerization reaction. From the start of the polymerization reaction to the end of the polymerization reaction, 40 g of a 0.1 wt% ascorbic acid aqueous solution was continuously added, and 3 hours after the start of the polymerization reaction,
Until the lapse of time, 20 g of a 5% sodium alkylsulfosuccinate aqueous solution was continuously added. The pressure in the polymerization vessel is 0.3
The polymerization reaction was stopped when the pressure was lowered to MPa, and the unreacted vinyl chloride monomer was recovered to obtain a polymerized latex containing vinyl chloride resin particles.

The vinyl chloride resin particles obtained had an average particle size of 0.72 μm and a THF-insoluble gel content of 91% by weight.

Then, 600 g of vinyl chloride monomer, 12 g of 1% by weight aqueous potassium persulfate solution and 2 g of 0.1% by weight aqueous ferrous sulfate solution were added to the polymerized latex containing the vinyl chloride resin particles, and the temperature was raised to 40.degree. After setting, an additional polymerization reaction was started. From the start of the additional polymerization reaction to the end of the additional polymerization reaction, 80 g of a 0.1 wt% ascorbic acid aqueous solution was continuously added, and 5% sodium alkylsulfosuccinate was added from 0.5 hours to 6 hours after the initiation of the additional polymerization reaction. 60 g of aqueous solution were added continuously. The pressure in the polymerization vessel is 0.
When the pressure dropped to 25 MPa, the additional polymerization reaction was stopped, unreacted vinyl chloride monomer was recovered, and a paste vinyl chloride resin latex was obtained.

The obtained paste vinyl chloride resin had an average particle size of 1.25 μm, and the outer skin layer formed by the additional polymerization reaction had a thickness of 0.265 μm.

Next, the paste vinyl chloride resin latex was dried by a rotary disk type spray dryer and collected as a paste vinyl chloride resin through a pulverizer.

The obtained paste vinyl chloride resin was evaluated in the same manner as in Example 1.

The evaluation results are shown in Table 1. Further, the results of observing the surface with an optical microscope are shown in FIG.

The obtained sheet had a high reflectance of 24.3% and was inferior in matteness. Further, the surface was flat with almost no unevenness observed.

Comparative Example 3 500 g of deionized water, 500 g of vinyl chloride monomer, 1.8 g of triallyl isocyanurate in a 2.5 l polymerization vessel,
36 g of seed particles obtained in Preparation Example 1 were charged with 10 g of a 5% sodium alkylsulfosuccinate aqueous solution and 8 g of a 0.1 wt% ferrous sulfate aqueous solution, and the temperature was then adjusted to 45.
The temperature was raised to ℃ and the polymerization reaction was started. From the start of the polymerization reaction to the end of the polymerization reaction, a 0.1 wt% aqueous ascorbic acid solution 80
g was continuously added, and further, 50 g of a 5% sodium alkylsulfosuccinate aqueous solution was continuously added from 1.5 hours to 6 hours after the initiation of the polymerization reaction. The polymerization reaction was stopped when the pressure inside the polymerization vessel dropped to 0.3 MPa, and unreacted vinyl chloride monomer was recovered to obtain a polymerized latex containing vinyl chloride resin particles.

The obtained vinyl chloride resin particles had an average particle size of 1.04 μm and a THF-insoluble gel content of 71% by weight.

Next, 300 g of vinyl chloride monomer, 6 g of 1% by weight aqueous potassium persulfate solution and 1 g of 0.1% by weight aqueous ferrous sulfate solution were added to the polymerized latex containing the vinyl chloride resin particles, and the temperature was raised to 40.degree. After setting, an additional polymerization reaction was started. After the start of the additional polymerization reaction, 40 g of an aqueous solution of% ascorbic acid was continuously added from 0.1 weight to the end of the additional polymerization reaction, and 5% alkylsulfosuccinic acid was added from 0.5 hours to 2 hours after the start of the additional polymerization reaction. 30 g of aqueous sodium solution was added continuously. The pressure in the polymerization vessel is 0.
When the pressure dropped to 25 MPa, the additional polymerization reaction was stopped, unreacted vinyl chloride monomer was recovered, and a paste vinyl chloride resin latex was obtained.

The obtained paste vinyl chloride resin had an average particle size of 1.19 μm, and the outer skin layer formed by the additional polymerization reaction had a thickness of 0.075 μm.

Next, the paste vinyl chloride resin latex was dried by a rotary disk type spray dryer and collected as a paste vinyl chloride resin through a pulverizer.

The obtained vinyl chloride resin for paste processing was evaluated in the same manner as in Example 1.

The evaluation results are shown in Table 1. Moreover, the result of surface observation by an optical microscope is shown in FIG.

The obtained sheet had a high reflectance of 18.2% and was inferior in matteness, and unevenness due to THF-insoluble matter was not observed so much on the surface.

[0083]

[Table 1]

INDUSTRIAL APPLICABILITY The matte paste vinyl chloride resin of the present invention can give a molded article having a dense matte surface and excellent mechanical strength characteristics, and its industrial value is extremely high. .

[Brief description of drawings]

FIG. 1 is an optical micrograph of the sheet obtained in Example 1.

FIG. 2 is an optical micrograph of the sheet obtained in Example 2.

FIG. 3 is an optical micrograph of the sheet obtained in Example 3.

FIG. 4 is an optical micrograph of the sheet obtained in Example 4.

5 is an optical micrograph of the sheet obtained in Comparative Example 1. FIG.

FIG. 6 is an optical micrograph of a sheet obtained in Comparative Example 2.

7 is an optical microscope photograph of the sheet obtained in Example 3. FIG.

Claims (2)

[Claims] 1. A vinyl chloride resin particle having an average particle size of 0.5 to 1.5 .mu.m containing 80% by weight or more of a tetrahydrofuran insoluble gel component as a core and having a thickness of 0.025 to 0.25 .mu.m.
Matting paste vinyl chloride resin characterized by having an outer layer of vinyl chloride resin of m. 2. A paste composition comprising the matte paste vinyl chloride resin according to claim 1 and a plasticizer and a stabilizer.