JPH0549704B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to composite polymer particles containing an inorganic filler and a method for producing the same. [Prior Art and Problems to be Solved by the Invention] Currently, thermoplastic resins are widely used in many industrial fields for reasons of weight reduction, but they have the drawback of low impact strength. Therefore, at present, the uses of thermoplastic resins are limited to those that are relatively immune to impact. Therefore, the present inventors have adopted a method of filling a thermoplastic resin with an impact modifier as a method of improving the impact resistance of the thermoplastic resin, and have been conducting research. As a result, it has been found that specific composite polymer particles containing an inorganic filler can be suitably used as an impact modifier for thermoplastic resins. Various types of composite polymer particles containing inorganic fillers are known. For example, JP-A-55-
Publication No. 106205 describes an inorganic fine particulate filler and (meth)
Polymer beads comprising polymers of acrylic esters are disclosed. However, such polymer beads have a one-layer structure in which the polymer portion is constructed. For this reason, when a polymer with a low glass transition temperature is used to make the polymer beads an impact modifier for a thermoplastic resin, the polymer beads coagulate with each other due to their tackiness. Therefore, the dispersibility of the polymer beads in the thermoplastic resin is not good, and satisfactory impact resistance cannot be obtained. Moreover, the thermoplastic resin filled with the above-mentioned polymer beads has the disadvantage that the surface hardness is reduced. Furthermore, in JP-A-59-1573, a mixture of a filler and a vinyl compound containing 15% by weight or more of a polyfunctional vinyl compound is subjected to suspension polymerization, and then in the presence of the obtained polymer, vinyl A method for carrying out the polymerization of compounds is described. However, the composite polymer particles obtained by this method contain polyfunctional vinyl compounds.
Since it contains more than 15% by weight, it is a hard polymer particle, and even if this polymer particle is filled into a thermoplastic resin, almost no impact improvement effect can be obtained as shown in Comparative Examples 2 and 4 described later. do not have. The present inventors have discovered that composite polymer particles containing an inorganic filler and having a two-layer structure of a polymer having a specific glass transition temperature are extremely useful as impact modifiers for thermoplastic resins. Ta. Moreover, when the composite polymer particles of the present invention are used as an impact modifier, there is an advantage that not only the impact resistance of the thermoplastic resin is improved, but also a decrease in the surface hardness of the thermoplastic resin can be prevented. . That is, the present invention has a glass transition temperature of 0° C. or lower and a crosslinkable vinyl monomer of 0.05 to 5% by weight,
A crosslinked vinyl copolymer (i) consisting of 99.95 to 95% by weight of a polymerizable vinyl monomer copolymerizable with the crosslinkable vinyl monomer, and a polymer consisting of silicon oxide, calcium carbonate or magnesium carbonate (ii). A composite polymer in which the surface of the combined particles is coated with a vinyl polymer (iii) having a glass transition temperature of 20°C or higher, has a two-layer structure, has an average particle size of 0.01 to 20μm, and has an angle of repose of 50° or less. It is a coalesced particle. Further, the present invention provides a material having a glass transition temperature of 0°C or lower, containing 0.05 to 5% by weight of a crosslinkable vinyl monomer, and 99.95 to 95% by weight of a polymerizable vinyl monomer copolymerizable with the crosslinkable vinyl monomer. % crosslinked vinyl copolymer (i) and silicon oxide, calcium carbonate or magnesium carbonate (ii), the surface of which is a vinyl polymer (iii) with a glass transition temperature of 20°C or higher. It has a two-layer structure and the average particle size is
An impact modifier comprising composite polymer particles having a diameter of 0.01 to 20 μm and an angle of repose of 50° or less is also provided. The composite polymer particles of the present invention have a two-layer structure including a polymer having a glass transition temperature of 0°C or lower and a polymer having a glass transition temperature of 20°C or higher. The polymer having a glass transition temperature of 0° C. or lower contains an inorganic filler and constitutes polymer particles. In addition, the glass transition temperature is 0
℃ or below, the polymer contains crosslinkable vinyl monomer units.
It is a vinyl copolymer containing 0.05 to 5% by weight. The polymer having a glass transition temperature of 0°C or lower may be used as long as it contains a crosslinkable vinyl monomer unit and has a glass transition temperature of 0°C or lower, and any known vinyl polymer can be used without any restriction. In the present invention, the glass transition temperature is -80°C to 0°C, and furthermore -70°C.
C. to 0.degree. C. is preferably used. As the vinyl monomer that provides a polymer having a glass transition temperature of 0° C. or lower, any known vinyl monomer can be used without particular limitation, but the vinyl monomers preferably used in the present invention are exemplified below. Then, the result is as follows. Acrylic acid alkyl esters having an alkyl group of 2 or more carbon atoms such as propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, decyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, etc. Examples include methacrylic acid alkyl esters having an alkyl group having 8 or more carbon atoms.
Moreover, the above vinyl monomer has a glass transition temperature of 0.
Use a vinyl monomer that gives a polymer with a temperature higher than 0°C, such as styrene, acrylonitrile, methyl methacrylate, α-methylstyrene vinyl chloride, etc., within a range where the glass transition temperature of the resulting vinyl copolymer is 0°C or lower. You can also do it. The above-mentioned polymer having a glass transition temperature of 0° C. or lower contains 0.05 to 5% by weight of crosslinkable vinyl monomer units. The crosslinkable vinyl monomer unit is derived from a crosslinkable vinyl monomer. As the crosslinkable vinyl monomer, any known vinyl monomer having two or more vinyl groups can be used without any restriction. Examples of crosslinkable vinyl monomers preferably used in the present invention include dimethacrylates such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and triethylene glycol dimethacrylate;
Diacrylates such as ethylene glycol diacrylate, diethylene glycol diacrylate, and triethylene glycol diacrylate; divinylbenzene, acryl tacrylate, triallylisocyanurate, and the like. Preferably, a highly lipophilic crosslinkable vinyl monomer is employed. The crosslinkable vinyl monomer unit preferably used in the present invention is a crosslinkable vinyl monomer unit derived from the above-mentioned crosslinkable vinyl monomer, and is represented by the following general formula. [However, R is a hydrogen atom or a methyl group, and
is -COO(CH ₂ CH ₂ O) nOC- (however, n is an integer of 1 or more) or

It is a group represented by [Formula]. ] In the above general formula, n is preferably 1 to 10 in consideration of the impact improving effect of the resulting composite polymer particles. The crosslinkable vinyl monomer unit must be contained in the polymer having a glass transition temperature of 0° C. or lower in an amount of 0.05 to 5% by weight. If the crosslinkable vinyl monomer unit is less than the above range, sufficient elasticity cannot be obtained and the resulting composite polymer particles cannot be used as an impact modifier. Moreover, when the amount exceeds the above range, the composite polymer particles become too hard and do not exhibit impact improving effects. On the other hand, as the other component constituting the polymer particles, inorganic fillers such as silicon oxide, calcium carbonate, or magnesium carbonate are suitably employed for the purpose of improving the impact of thermoplastic resins. The average particle size of the inorganic filler is preferably 10 μm or less, more preferably 2 μm or less in order to exhibit the impact improving effect. When using the obtained composite polymer particles as an impact modifier, the ratio of the polymer having a glass transition temperature of 0° C. or lower and the inorganic filler constituting the polymer particles is as follows:
It is preferable that the amount of the inorganic filler is in the range of 1 to 400 parts by weight per 100 parts by weight of the polymer having a glass transition temperature of 0° C. or lower. More preferably, the amount is in the range of 5 to 200 parts by weight. The polymer particles described above are coated with a vinyl polymer having a glass transition temperature of 20° C. or higher. The vinyl polymer having a glass transition temperature of 20° C. or higher may be either a homovinyl polymer or a vinyl copolymer, and any known vinyl polymer may be used without any restriction. In the present invention, vinyl polymers having a glass transition temperature of 20 to 150°C, more preferably 30 to 140°C, are particularly preferably used. The glass transition temperature is 20
As the vinyl monomer that provides a vinyl polymer having a temperature of .degree. C. or higher, any known vinyl monomer can be used without any restriction. Examples of vinyl monomers particularly preferably used in the present invention include methacrylates having an alkyl group having 4 or less carbon atoms in the ester bonding moiety, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. Examples include acid alkyl esters; methyl acrylate; aromatic vinyl compounds such as styrene and α-methylstyrene; unsaturated nitrile compounds such as acrylonitrile; and vinyl chloride. Further, even if the vinyl monomer provides a vinyl polymer having a glass transition temperature of 20°C or less, there will be no problem if it is used within a range where the resulting copolymer has a glass transition temperature of 20°C or higher. When using the resulting composite polymer particles as an impact modifier, the above-mentioned vinyl polymers with a glass transition temperature of 20°C or higher should be used in consideration of dispersibility in thermoplastic resins and improvement of impact resistance. coalesced particles
10 to 500 parts by weight per 100 parts by weight, and further 20 to 500 parts by weight
It is preferable to use it in a range of 200 parts by weight. The thickness of the coating layer of the vinyl polymer having a glass transition temperature of 20°C or higher is not particularly limited, but is generally 0.002 μm to 0.002 μm by using the vinyl polymer within the above range.
8 μm, preferably in the range of 0.002 to 0.8 μm. When improving the impact resistance of a thermoplastic resin using the composite polymer particles of the present invention, the optimum particle size range may be selected depending on the type of thermoplastic resin.
Generally, the average particle size is 0.01~20μm, and even
It is preferably in the range of 0.05 to 2 μm. In addition, the composite polymer particles of the present invention generally have 70%
The above preferably shows a gel content of 80% or more. Since the surface of the composite polymer particles of the present invention is coated with a vinyl polymer having a high glass transition temperature,
It is a powder and has good fluidity. Furthermore, the angle of repose of the powder generally shows a value of 50° or less. Furthermore, the inorganic filler in the composite polymer particles of the present invention is completely covered with the polymer and is not exposed on the surface of the composite polymer particles. This is supported by the fact that when calcium carbonate is used as an example of an inorganic filler in composite polymer particles, most of the calcium carbonate is not eluted even after being treated with an HCL acidic solution of pH 1.0 for 1 hour. . The method for producing the composite polymer particles of the present invention described above is not particularly limited, but a preferred production method is as follows. That is, for a vinyl monomer that provides a polymer with a glass transition temperature of 0°C or less, and for the vinyl monomer,
0.05 to 5% by weight of a crosslinkable vinyl monomer is subjected to suspension polymerization in an aqueous medium using an oil-soluble radical initiator in the presence of an inorganic filler, and then the polymer obtained by the suspension polymerization is The glass transition temperature is 20℃ in the presence of
This is a method of suspension polymerizing vinyl monomers to produce the above vinyl polymer. A vinyl monomer that provides a polymer with a glass transition temperature of 0° C. or less, the above-mentioned crosslinkable vinyl monomer and an inorganic filler in an amount of 0.05 to 5% by weight based on the vinyl monomer are thoroughly mixed. This is then uniformly dispersed in an aqueous medium, and the first stage polymerization is carried out using an oil-soluble radical initiator. Here, as mentioned above, the amount of inorganic filler used is 100% of the vinyl monomer that provides a polymer with a glass transition temperature of 0°C or less.
The amount is preferably 1 to 400 parts by weight. In addition, the inorganic filler and glass transition temperature are 0℃
In order to obtain a homogeneous mixture with the following polymer and to obtain composite polymer particles suitable as an impact modifier, the viscosity of the vinyl monomer that provides the polymer with a glass transition temperature of 0°C or less must be adjusted. It is preferable to adjust to a range of 5 to 50,000 centipoise. The following method is employed to adjust the viscosity of the vinyl monomer within the above range. A method in which a vinyl monomer that provides a polymer with a glass transition temperature of 0° C. or less is partially polymerized in advance to generate an oligomer and increase the viscosity. A method of dissolving a polymer for viscosity adjustment within a range that does not affect the glass transition temperature in a vinyl monomer that provides a polymer with a glass transition temperature of 0° C. or lower. A method of mixing a vinyl monomer that provides a polymer with a glass transition temperature of 0° C. or less with a vinyl monomer having a high viscosity within a range that does not affect the glass transition temperature. In the above method, the viscosity is determined by the glass transition temperature being 0.
Since it is influenced by the polymerization time of the vinyl monomer, polymerization temperature, initiator concentration, and monomer concentration to give a polymer having a temperature of 0.degree. C. or less, it is preferable to investigate the relationship between the viscosity and these factors in advance. Furthermore, it is preferable that the glass transition temperature of the polymer used in the above method for adjusting the viscosity be 0°C or lower; however, even if the glass transition temperature exceeds 0°C, the resulting polymer The glass transition temperature of coalescence is 0
It can be used within a temperature range below ℃. Examples of the above-mentioned polymer for adjusting the viscosity include an acrylic ester polymer having an alkyl group having 1 to 10 carbon atoms, or a methacrylic ester polymer,
Examples include styrene polymers, butadiene polymers, isobutylene polymers, styrene-butadiene copolymers, chlorinated ethylene polymers, ethylene-propylene copolymers, and the like. More preferably, polymers having reactive groups are used. Examples include those having a peroxy group in the polymer, such as n-butyl acrylate polymer, styrene polymer, and methyl methacrylate polymer. Also included are polymers having vinyl groups at the ends obtained by reacting a polymer having an azo group in the main chain with a polymer having thioglycolic acid at the ends and glycidyl methacrylate. When adjusting the viscosity using the above polymer, the amount may be such that the viscosity is in the range of 5 to 50,000 centipoise. Generally, a vinyl monomer that provides a polymer with a glass transition temperature of 0°C or less
The above polymer may be used in an amount of 0.5 to 40 parts by weight, more preferably 1 to 30 parts by weight, per 100 parts by weight. Further, examples of the high viscosity vinyl monomer used in the above method include vinyl compounds having a polymer in the side chain. Examples of such vinyl monomers include mono(meth)acrylates having propylene glycol polymers, alkyl(meth)acrylate polymers, urethane polymers, ester polymers, etc. in their side chains. The amount used may be within the same range as the above-mentioned polymer for viscosity adjustment. As the oil-soluble radical initiator used in the first stage polymerization of the present invention, known ones can be used without any restrictions. The second step is to carry out suspension polymerization of a vinyl monomer to give a polymer having a glass transition temperature of 20°C or higher in the presence of the polymer particles obtained in the first stage polymerization of the present invention.
In the step polymerization, it is preferable not to newly add an oil-soluble radical initiator in order to prevent the formation of new particles by the vinyl monomer that provides a vinyl polymer with a glass transition temperature of 20° C. or higher. Therefore, the first
It is preferable that a part of the oil-soluble radical initiator added in the stage polymerization is used in the first stage polymerization, and the remainder is used in the second stage polymerization. The amount of oil-soluble radical initiator used in the first stage polymerization is preferably 30-40% by weight of the amount used in the entire polymerization process. As a specific method for adjusting the amount of the oil-soluble radical initiator used in the first stage polymerization and the second stage polymerization, the following method is preferably employed. Add two or more types of oil-soluble radical initiators with different decomposition temperatures, use a low-temperature active oil-soluble radical initiator in the first stage polymerization, and use a high-temperature active oil-soluble radical initiator in the second stage polymerization. . In the above method, oil-soluble radical initiators with different decomposition temperatures have a 10-hour half-life temperature of 50°C.
It is preferable to use the following initiators together with an initiator having a temperature of 50°C or more, and further initiators whose half-life temperatures differ by 10°C or more. 1st when half-life temperature is below 50℃ for 10 hours
Examples of the initiator consumed in the stage polymerization step include isobutyryl peroxide, diisopropyl peroxydicarbonate, dimyristyl peroxydicarbonate, di(2-ethoxyethyl) peroxydicarbonate, cumyl peroxyneodecanate, etc. can be mentioned. On the other hand, examples of initiators whose 10-hour half-life temperature is 50°C or higher and which are mostly consumed in the second stage polymerization step include t-butyl peroxyhybarate, lauroyl peroxide, benzoyl peroxide, and azobisisobutyroyl peroxide. Examples include nitrile. The amount of the above-mentioned low temperature active initiator and high temperature active initiator is 0.5 parts by weight per 100 parts by weight of the total vinyl monomer.
It is preferable that the amount is 5 parts by weight, of which the ratio of the low temperature active initiator is preferably 30 to 40% by weight. More preferably, an oil-soluble initiator having a structure that is resistant to hydrolysis by alkali is used. In the present invention, it is preferable to use a surfactant in the first stage polymerization in order to adjust the particle diameter of the resulting composite polymer particles to a value suitable for use as an impact modifier. Examples of the surfactant include ordinary anionic, cationic, or nonionic surfactants, and these can be used alone or in combination. Suitable surfactants in the present invention include sodium lauryl sulfonate, sulfosuccinic acid ester sodium salt, potassium oleate, polyethylene glycol, monooleyl ether, and the like. The above-mentioned surfactant is used in the first stage polymerization process to disperse the inorganic filler and the vinyl monomer uniformly and to prevent the resulting polymer particles from agglomerating. It is suitable to use 0.5 to 25 parts by weight, preferably 1 to 20 parts by weight, per 100 parts by weight of the filler mixture. The polymerization conditions for the first stage polymerization are not particularly limited, but
Temperatures and polymerization times suitable for decomposition of the oil-soluble radical initiator described above are selected. Generally, the polymerization temperature may be selected from the range of 40 to 90°C, preferably 50 to 85°C, and the polymerization time may be selected from the range of 30 to 240 minutes.
The amount of water used in suspension polymerization is preferably in the range of 250 to 2000 parts, assuming that the total amount of the inorganic filler and all monomers is 100 parts. Furthermore, at this time, it is suitable that the pH of the aqueous medium is 7 or higher, preferably 8 or higher. In the presence of the polymer particles obtained in the first stage polymerization, a second stage polymerization is carried out in which suspension polymerization of a vinyl monomer is carried out to give a vinyl polymer having a glass transition temperature of 20°C or higher. Ru. Glass transition temperature is 20
As the vinyl monomer that provides a vinyl polymer having a temperature of .degree. C. or higher, the above-mentioned vinyl monomers are employed.
The amount of the vinyl monomer used is preferably in the range of 10 to 500 parts by weight based on 100 parts by weight of the polymer particles obtained in the first stage polymerization. In addition, in the second stage polymerization, a water-soluble polymerization inhibitor may be used to prevent the formation of new particles due to the polymerization of the vinyl monomer that yields a polymer with a glass transition temperature of 20°C or higher. preferable. Polymerization inhibitors suitably used in the present invention include ammonium thiocyanate, sodium nitrite, and the like. These polymerization inhibitors are vinyl monomers added in the second stage polymerization.
It is preferable to use it in a range of 0.1 to 5 parts by weight per 100 parts by weight in terms of the polymerization inhibiting effect and prevention of agglomeration between polymer particles. In the second stage polymerization, the same surfactant as used in the first stage polymerization can be used if necessary. The polymerization conditions for the second stage polymerization may be those suitable for the oil-soluble radical initiator added in the first stage polymerization. Generally, the polymerization temperature in the second stage polymerization step is 40 to 90°C, preferably 50 to 85°C, and the polymerization time is preferably selected from the range of 1 hour to 36 hours. The vinyl monomer may be added by either a batch addition method or a sequential addition method, but the sequential addition method is more preferably used. The composite polymer particles obtained as described above are subjected to centrifugal sedimentation or salting out aggregation, filtered, and thoroughly dried to obtain a powder. The composite polymer particles of the present invention can be used as an impact modifier by being mixed with a thermoplastic resin such as vinyl chloride resin or olefin resin. At this time, the blending ratio may be determined depending on the usage conditions of the intended molded article, but it is usually preferable to use 1 to 30 parts by weight of the composite polymer particles per 100 parts by weight of the thermoplastic resin. Further, commonly used auxiliary materials such as stabilizers, ultraviolet absorbers, antioxidants, dyes and pigments can be added as necessary. [Effects] The composite polymer particles of the present invention have the effect of improving the impact resistance in thermoplastic resins, have good dispersibility in thermoplastic resins, and can be used in machines using inorganic fillers. It also has a reinforcing effect. Therefore, when the composite polymer particles of the present invention are filled into a thermoplastic resin, the impact resistance of the thermoplastic resin is improved, and the decrease in surface hardness that is accompanied by the improvement in impact resistance is prevented. can do. Furthermore, the phenomenon in which the filler migrates to the surface of the thermoplastic resin over time is not observed at all when the composite polymer particles of the present invention are used. Therefore, the polymer of the present invention is extremely useful as an impact modifier for thermoplastic resins. In order to explain the present invention more specifically, the following examples will be given and explained, but the present invention is not limited to these examples. The various measured values shown in Examples and Comparative Examples were based on the following measurement methods. 1 Viscosity: 23℃ using Toyo Keiki visconic ELD
Measurements were made with 2 Particle size: Measured using a centrifugal particle size distribution analyzer manufactured by Horiba, Ltd. CAPA-500. Alternatively, it was observed using a scanning electron microscope manufactured by JEOL Ltd. 3 Inorganic filler content: Shimadzu Thermal Analyzer
It was determined by weight change using DT30 model. 4. Angle of repose: Determined by funnel injection method and free accumulation method. 5. Gel content: Using toluene as a solvent, weigh out 0.1% by weight of composite polymer particles based on the solvent, and let stand in the solvent at room temperature for 20 to 24 hours. Next, dry under reduced pressure and then dry in a dryer at 105°C until a constant weight is reached. The weight at this time was measured and the gel content was calculated using the following formula. Gel content (%) = weight after drying / weight of collected composite polymer particles x 100 6 Thickness of coating layer: Using the method for measuring the particle size determined in section 2, The thickness of the polymer coating layer with a glass transition temperature of 20° C. or higher was calculated from the difference between the resulting particle size and the final particle size obtained in the second stage polymerization step. 7. Charpy impact strength: Measured at 23°C in accordance with JIS K-7111. 8 Tensile test: Measured at 23°C in accordance with JIS K-7113. 9 Hardness: Measured using a Brinell hardness meter. Example 1 95 parts by weight of n-butyl acrylate and n-acrylic acid
5 parts by weight of -butyl polymer (molecular weight: 300,000) were uniformly mixed to obtain an n-butyl acrylate mixture having a viscosity of 1700 cp. The above n-butyl acrylate mixture
To 100 parts by weight, 2 parts of ethylene glycol dimethacrylate, 15 parts of diisopropyl peroxydicarbonate, and 3 parts of benzoyl peroxide were added and mixed, and then 50 parts of calcium carbonate with an average particle size of 0.08 μm (Shiraishi Kogyo Co., Ltd., Hakuenka R-06) was added. of the mixture was added and mixed uniformly under ice-cooling. Furthermore, a mixed solution of 2,500 parts of ion-exchanged water and 20 parts of di-2-ethylhexyl sulfosuccinate sodium was added, and emulsification and dispersion was carried out at 10,000 rpm for 10 minutes under ice cooling. After adjusting the pH of the mixture thus obtained to 9.5, it was charged into a reaction vessel equipped with a cooler and a stirrer, and after being sufficiently purged with nitrogen, polymerization was carried out at 70°C for 3 hours. The polymerization yield at this time was 98%. continue
Add 0.25 parts of ammonium thiocyanate at 70°C, stir for 10 minutes, then add 50 parts of methyl methacrylate to 1 part.
After the dropwise addition over a period of time, the reaction was further carried out for 10 hours. The obtained composite polymer particles were determined to have a diameter of 0.5 μm by centrifugal sedimentation. The resulting mixed solution was salted out and coagulated with sodium chloride, then dehydrated, washed, and dried. The yield of the obtained composite polymer particles was 97%, the calcium carbonate content was 25.2% by weight, the angle of repose was 34°, and the gel content was 96.3% by weight.
Further, the thickness of the coating layer was 0.1 μm. 10 parts of the composite polymer particles obtained above were added to 100 parts of vinyl chloride resin with an average degree of polymerization of 1300 and lead stearate.
4.2 parts were mixed and kneaded at 180°C for 10 minutes using hot rolls, followed by press molding at 185°C for 15 minutes to prepare test pieces. Sharpie impact strength according to JIS-K-7111, JIS
A tensile test was conducted using -K-7113. Further, the surface hardness was determined by using a Brinell hardness tester after 30 seconds. As a result, the Charpy impact strength was 21.8 Kgfcm/cm ² , the tensile strength was 460 Kg/cm ² , the elongation was 185%, and the Brinell hardness was 17.4. Examples 2 and 3 The same method was used except that the calcium carbonate used in Example 1 was replaced with another inorganic filler. However, the PH
8.0 and polymerization was carried out. In the same manner as in Example 1, 10 parts by weight of the above composite polymer particles and 100 parts by weight of vinyl chloride resin were mixed to prepare a test piece and measurements were performed. The results are shown in Table 1.

[Table] Examples 4 to 7 Vinyl monomers that give a polymer with a glass transition temperature of 0°C or lower, vinyl monomers that give a polymer with a glass transition temperature of 20°C or higher, and Composite polymer particles were obtained in the same manner as in Example 1, except that the polymer for viscosity adjustment was changed to those shown in Table 2. The properties of the obtained composite polymer particles are also shown in Table 2. In the same manner as in Example 1, vinyl chloride resin
Table 3 shows the properties of test pieces obtained from 100 parts by weight and 10 parts by weight of the composite polymer particles.

【table】

【table】

[Table] Example 8 The same method as in Example 1 was carried out except that the oil-soluble radical initiator used in Example 1 and the polymerization temperature were changed as shown in Table 4. However, the pH of the system was adjusted to 9.5 for polymerization. The polymerization results are shown in Table 4, and the results obtained by preparing a test piece by mixing 10 parts by weight of composite polymer particles and 100 parts by weight of vinyl chloride resin in the same manner as in Example 1 are shown in Table 5.
Shown in the table.

【table】

[Table] Example 9 The same method was used except that the 2 parts of ethylene glycol dimethacrylate used in Example 1 was changed to 0.5 parts, 1 part, and 4 parts. However, the pH of the system was adjusted to 9.5. Table 6 shows the polymerization results and the results obtained by preparing test pieces by mixing 10 parts by weight of composite polymer particles and 100 parts by weight of vinyl chloride resin in the same manner as in Example 1.

[Table] Example 10 The same method was followed except that 20 parts of sodium di-2-ethylhexyl sulfosuccinate used in Example 1 was replaced with 20 parts of sodium lauryl sulfonate. However, the pH of the system was adjusted to 9.0 for polymerization.
The particle diameter of the obtained composite polymer particles was 0.4 μm, the yield was 97%, the calcium carbonate content was 25.6%, and the angle of repose was 35°. Also, the gel content is 95.7%
The thickness of the coating layer was 0.05 μm. As in Example 1, 10 parts by weight of the above polymer particles and vinyl chloride resin
A test piece was prepared by mixing 100 parts by weight, and measurements were taken.
As a result, the Shalpy impact strength was 20.9Kgfcm/cm ²
The tensile strength was 475 Kg/cm ² , the elongation was 185%, and the Brinell hardness was 18.0. Comparative Example 1 The same method as in Example 1 was carried out except that the calcium carbonate used in Example 1 was not mixed. The particle size was 0.4 μm and the yield was 97%. The angle of repose was 39°C. Polymer particles obtained above
7.5 parts by weight and 2.5 parts by weight of Hakuenka (R-06) were mixed with 100 parts by weight of vinyl chloride resin in the same manner as in Example 1 to prepare a test piece. The results are shown in Table 7. Comparative Example 2 The same method as in Example 1 was carried out except that 2 parts by weight of ethylene glycol dimethacrylate used in Example 1 was changed to 20 parts by weight. The particle size was 0.6 μm and the yield was 98%. or,
The angle of repose was 33°. 10 parts by weight of the composite polymer particles thus obtained were mixed with 100 parts by weight of vinyl chloride resin in the same manner as in Example 1 to prepare a test piece.
The results are shown in Table 7. Comparative Example 3 The same method as in Example 1 was carried out except that methyl methacrylate was not added. The particle size was 0.4 μm and the yield was 98%. The composite polymer could not be obtained as particles, but instead formed a viscous agglomerate, making it impossible to measure the angle of repose. The composite polymer thus obtained was cut into pieces and mixed with vinyl chloride resin in the same manner as in Example 1 to prepare test pieces. The results are shown in Table 7. Comparative Example 4 The following experiment was conducted on composite polymer particles in which the glass transition temperature of the polymer particles did not fall below 0°C. 150 g of styrene, 150 g of divinylbenzene, 20 g of diisopropyl peroxydicarbonate, 5 g of benzoyl peroxide, 6 g of tertiary lead decyl mercaptan, and calcium carbonate with an average particle size of 0.08 μm (manufactured by Shiraishi Kogyo Co., Ltd., Hakuenka R-06) 60
g and uniformly mixed under ice cooling. Further, a mixed solution of 3,000 g of ion-exchanged water and 30 g of di-2-ethylhexyl sulfosuccinate sodium was added, and emulsification and dispersion was carried out at 10,000 rpm for 10 minutes under ice cooling. After adjusting the pH of the mixture thus obtained to 8.0, it was charged into a reaction vessel equipped with a cooler and a stirrer, and after sufficient element replacement, polymerization was carried out at 70°C for 5 hours. Next, the temperature was raised to 75℃, 0.3g of ammonium thiocyanate was added, and after stirring for 10 minutes, the styrene
A mixture of 80 g of acrylonitrile and 20 g of acrylonitrile was added dropwise over 1 hour, and then polymerization was continued for an additional 15 hours. The average particle diameter of the obtained composite polymer particles was 0.9μ
It was m. The obtained mixture was coagulated by salting out with sodium chloride, then dehydrated, washed, and dried.
The yield of the obtained composite polymer particles was 95%, the calcium carbonate content was 8% by weight, the angle of repose was 31°,
Gel content was 97.1% by weight. In the same manner as in Example 1, 10 parts by weight of the above composite polymer particles and 100 parts by weight of vinyl chloride resin were mixed to prepare a test piece and measurements were performed. As a result, the Shalpy impact strength was 5.2Kgfcm/
cm ² , tensile strength 40 Kg/cm ² , elongation 70%, and Brinell hardness 18.3.

[Table] Comparative Examples 5 to 7 The same method was used except that the calcium carbonate used in Example 1 was replaced with another inorganic filler. However, the PH
8.0 and polymerization was carried out. In the same manner as in Example 1, 10 parts by weight of the above composite polymer particles and 100 parts by weight of vinyl chloride resin were mixed to prepare a test piece and measurements were performed. The results are shown in Table 8.

【table】

Claims (1)

[Scope of Claims] 1. 99.95% of a polymerizable vinyl monomer having a glass transition temperature of 0° C. or lower and copolymerizable with 0.05 to 5% by weight of a crosslinkable vinyl monomer and the crosslinkable vinyl monomer.
~95% by weight of a crosslinked vinyl copolymer (i) and silicon oxide, calcium carbonate or magnesium carbonate
Polymer particles consisting of (ii) are coated on the surface with vinyl polymer (iii) having a glass transition temperature of 20°C or higher to form a two-layer structure and have an average particle size of 0.01 to 20 μm,
Composite polymer particles with an angle of repose of 50° or less. 2 A polymerizable vinyl monomer having a glass transition temperature of 0° C. or lower and copolymerizable with 0.05 to 5% by weight of a crosslinkable vinyl monomer and the crosslinkable vinyl monomer 99.95
~95% by weight of a crosslinked vinyl copolymer (i) and silicon oxide, calcium carbonate or magnesium carbonate
Polymer particles consisting of (ii) are coated on the surface with vinyl polymer (iii) having a glass transition temperature of 20°C or higher to form a two-layer structure and have an average particle size of 0.01 to 20 μm,
An impact modifier made of composite polymer particles with an angle of repose of 50° or less.