TWI551614B - Polymer compound, and manufacturing method and molded article thereof - Google Patents

Description

Polymer compound, its production method and molded article

The present invention relates to a polymer compound excellent in transparency, fluidity, and impact resistance, and a method for producing the polymer compound with high production efficiency and a molded article comprising the polymer compound.

The polymer compound produced by radical polymerization is used as a molded article in the field of office automation (OA) equipment, automotive, and electrical. Various uses such as the electronics field. For example, a polymer compound having transparency as a representative of a methacrylic resin is widely used for optical applications of a front plate and a light guide plate of a so-called display device.

In recent years, with the increase in size and thickness of display devices, there is a need to improve the moldability of a polymer compound such as a methacrylic resin.

The moldability of the polymer compound can be improved by reducing the weight average molecular weight, thereby improving the fluidity, but the impact resistance of the obtained molded article is lowered.

It is known that an impact resistance improver is added in order to have both moldability and impact resistance in a methacrylic resin. For example, it is known that a monomer mixture is polymerized by coexisting a specific block copolymer as an impact resistance improver, and a methacrylic resin composition excellent in impact resistance can be obtained (see Patent Document 1). However, this method has a problem that the production process becomes complicated and the transparency of the obtained methacrylic resin composition is impaired, and there is still room for improvement.

Advanced technical literature Patent literature

Patent Document 1 JP-A-2011-12236

[Summary of the Invention]

Accordingly, an object of the present invention is to provide an industrially advantageous production method of a polymer compound which is excellent in moldability and impact resistance, which is suitable for transparency in optical use, and a polymer obtained by the production method. Compound. Further, another object of the present invention is to provide a molded article excellent in appearance obtained from the polymer compound.

According to the present invention, the above object is achieved by providing the following [1] to [5].

[1] A method for producing a polymer compound, which is a monomer mixture (C) comprising a methacrylate (A) and a vinyl monomer (B) copolymerizable with the methacrylate (A) And a method for producing a polymer compound which undergoes radical polymerization in the presence of one or more kinds of polyfunctional chain transfer agents (D) and a polymerization initiator (E), wherein the monomer mixture (C) is contained in an amount of 100 parts by mass or less The amount of the above-mentioned polyfunctional chain transfer agent (D) to be used satisfies the relationship of the following formula (1);

(In the formula (1), a and p represent an integer of 1 or more, and M _p , n _p and W _p respectively represent any polyfunctional chain transfer agent (D _p ) of the a polyfunctional chain transfer agent (D). Molecular weight, number of functional groups, and amount (parts by mass).

[2] A method for producing a polymer compound, which is a monomer mixture (C) comprising a methacrylate (A) and a vinyl monomer (B) copolymerizable with the methacrylate (A) And a method for producing a polymer compound which undergoes radical polymerization in the presence of one or more kinds of polyfunctional chain transfer agents (D), one or more kinds of monofunctional chain transfer agents (D'), and a polymerization initiator (E), The amount of the above-mentioned polyfunctional chain transfer agent (D) and the aforementioned monofunctional chain transfer agent (D') relative to 100 parts by mass of the above monomer mixture (C) is satisfied by the following formula (2) and formula (3). )Relationship;

(In the formulas (2) and (3), a, b, and p each represent an integer of 1 or more, and M _p , n _{p ,} and W _p respectively represent any polyfunctional chain of the a polyfunctional chain transfer agent (D). The molecular weight, the number of functional groups and the amount (parts by mass) of the transfer agent (D _p ), and M' _p and W' _p respectively represent any monofunctional chain transfer agent (D' of the b monofunctional chain transfer agent (D'). The molecular weight and amount (parts by mass) of _p ).

[3] The method for producing a polymer compound according to any one of the above [1] or [2], wherein the polymerization initiator (E) is used in an amount of 0.001 to 0.01 parts by mass;

[4] A polymer compound obtained by the production method according to any one of the above [1] to [3];

[5] A molded article comprising the polymer compound described in the above [4].

According to the production method of the present invention, it is not necessary to add an impact-resistant improver, and it is possible to industrially advantageously produce a polymer compound having transparency suitable for optical use and excellent in moldability and impact resistance. Moreover, the molded article obtained by the production method can provide a molded article excellent in mechanical strength and appearance.

[Formation for implementing the invention]

In the method for producing a polymer compound of the present invention, a monomer mixture (C) comprising a methacrylate (A) and a vinyl monomer (B) copolymerizable therewith, and one or more polyfunctional groups are used. Radical polymerization is carried out in the presence of a chain transfer agent (D) and a polymerization initiator (E).

The radical polymerization system in the production method of the present invention can be adapted The solution polymerization method, the suspension polymerization method, the bulk polymerization method, the emulsion polymerization method, or the like can be carried out by any of a batch method and a continuous polymerization method. Among them, in particular, in the optical use of the obtained polymer compound, a bulk polymerization method which does not use a dispersant, an emulsifier, a solvent or the like is preferable, and from the viewpoint of productivity, it is preferable to use Block polymerization method of continuous polymerization (continuous block polymerization method).

As a methyl propylene which can be used in the production method of the present invention The enoate (A) can be exemplified by methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl methacrylate, methacrylic acid ( An alkyl methacrylate such as 2-ethylhexyl ester; a cycloalkyl methacrylate such as cyclohexyl methacrylate or methacrylic acid (t-butylcyclohexyl ester); or a benzyl methacrylate; An aryl methacrylate; an aryl methacrylate such as phenyl methacrylate. Among them, in particular, from the viewpoint of transparency of the obtained polymer compound, it is preferred to use an alkyl methacrylate. These methacrylates (A) may be used alone or in combination of plural kinds.

As a manufacturing method that can be used in the present invention, The methacrylic ester (A) copolymerized vinyl monomer (B) can be exemplified by methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, hexyl acrylate, acrylic acid (2- Acrylates of ethylhexyl acrylate, cyclohexyl acrylate, acrylic acid (t-butylcyclohexyl ester), benzyl acrylate, phenyl acrylate, etc.; styrene, α-methylstyrene, α-ethylstyrene , α-propyl styrene, α-butyl styrene, α-pentyl styrene, α-hexyl styrene, α-octyl styrene, m-methyl styrene, m-ethyl Styrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-di An aromatic vinyl compound such as methyl styrene, p-tert-butyl styrene or α,α-diphenylethylene; maleic anhydride, methyl maleic anhydride, dimethyl butylene An unsaturated carboxylic anhydride such as an anhydride, methylene succinic anhydride, aconitic anhydride or trimellitic anhydride; N-methyl maleimide, N-ethyl maleimide, N-benzene a maleimide such as cis-butenylenediamine or N-cyclohexylmethyleneimine; a decylamine such as acrylamide or methacrylamide; acrylonitrile or methacryl A cyanide vinyl compound such as a nitrile. Among them, in particular, from the viewpoint of transparency of the obtained polymer compound, an acrylate is preferred, and an alkyl acrylate having a carbon number of 1 to 6 is preferably used. These vinyl monomers (B) may be used singly or in combination of plural kinds.

Monomer mixture used in the manufacturing method of the present invention (C) is preferably a methacrylate (A) in an amount of from 50 to 99.9% by mass, more preferably from 70 to 99.5% by mass, more preferably from the viewpoint of transparency and formability. Contains a range of 85 to 99% by mass. Further, the monomer mixture (C) is preferably a vinyl monomer (B) in an amount of from 0.1 to 50% by mass, preferably from 0.5 to 30% by mass, more preferably from 1 to 15% by mass. The range of %.

Further, the above monomer mixture (C) is comprised of 99 to 100 The monofunctional monomer in the range of % by mass is preferably in the range of 99.5 to 100% by mass, more preferably in the range of 99.9 to 100% by mass, and most preferably 100% by mass. When a polyfunctional monomer is contained, the molecular weight distribution becomes wide, and the effect of this invention cannot fully be acquired, and the light transmittance of a molded article is also low.

In the manufacturing method of the present invention, by making a multifunctional chain The use amount of the transfer agent (D) is such that the above-mentioned monomer mixture (C) satisfies the relationship of the following formula (1), and the moldability and impact resistance of the obtained polymer compound can be improved.

(In the formula (1), a and p represent an integer of 1 or more, and M _p , n _p and W _p respectively represent any polyfunctional chain transfer agent (D _p ) of the a polyfunctional chain transfer agent (D). Molecular weight, number of functional groups and amount (parts by mass)).

The polyfunctional chain transfer agent (D) used in the production method of the present invention means a chain transfer agent having two or more functional groups having a chain transfer constant of 0.01 or more in one molecule under radical polymerization conditions. Further, the above-mentioned chain transfer constant means a chain of a terminal end radical of a polymer containing a monomer mixture (C) at a radical polymerization temperature and a functional group of the polyfunctional chain transfer agent (D). The transfer constant is defined as the velocity constant k _tr of the chain transfer reaction divided by the value of the rate constant k _p of the growth reaction. Examples of such a functional group include a mercapto group, a disulfide group, and a halogen group.

As the polyfunctional chain transfer agent (D), 1,4-butanedithiol, 1,6-hexanedithiol, 1,10-decanedithiol, ethylene glycol dithiopropionate, and butyl can be exemplified. Glycol dithioethylene glycol ester, butanediol dipropionate, hexanediol dithioethylene glycol ester, hexanediol dithiopropionate, trimethylolpropane trithiopropionate An alkyl mercaptan such as pentaerythritol tetrathiopropionate or dipentaerythritol hexathiopropionate. These polyfunctional chain transfer agents (D) may be used singly or in combination of plural kinds.

The amount of the polyfunctional chain transfer agent (D) used per 100 parts by mass of the monomer mixture (C) must satisfy the above formula (1). That is, all of the multifunctional chain transfer agents (D) used. n ^0.5 /M (W, n, M represents the sum of the molecular weight, the number of functional groups and the amount (parts by mass) of each polyfunctional chain transfer agent (D) (hereinafter referred to as "constant f") is 0.0015 or more and 0.0045. the following. When W mass parts of a polyfunctional chain transfer agent (D) having a molecular weight of M and a functional group of n are used with respect to 100 parts by mass of the monomer mixture (C), it is inferred that chain transfer of the growing terminal radical in the radical polymerization occurs. The substituent is 100 parts by mass of the monomer mixture (C). n ^0.5 / M Moule. Therefore, the constant f means a total of the number of functional groups of the polyfunctional chain transfer agent (D) in which the terminal radical chain transfer is grown at the time of radical polymerization of 100 parts by mass of the monomer mixture (C). If the constant f is less than 0.0015, the fluidity tends to be low, and if it is more than 0.0045, the flushing resistance tends to be low. The constant f is preferably in the range of 0.0020 to 0.0040, preferably in the range of 0.0025 to 0.0035.

Further, in the radical polymerization by the production method of the present invention, the monofunctional chain transfer agent (D') can be further used. The monofunctional chain transfer agent (D') used in the production method of the present invention means a chain transfer agent having only one functional group having a chain transfer constant of 0.01 or more in one molecule under radical polymerization conditions. Further, the above-mentioned chain transfer constant means a growth terminal radical of a polymer containing a monomer mixture (C) at a radical polymerization temperature and a functional group of the monofunctional chain transfer agent (D'). The chain transfer constant is defined as the value of the rate constant k _tr of the chain transfer reaction divided by the rate constant k _p of the growth reaction. Examples of such a functional group include a mercapto group, a disulfide group, and a halogen group.

Examples of the monofunctional chain transfer agent (D') include alkyl mercaptans such as n-octyl mercaptan, n-dodecyl mercaptan, and thirteen-dodecyl mercaptan; and thioglycolic acid. Ester; 3-mercaptopropionate; thiophenol; alkyl sulfide; α -methylstyrene dimer, etc., particularly preferably alkyl mercaptan. These monofunctional chain transfer agents (D') may be used singly or in combination of plural kinds.

Multifunctional chain transfer when using a monofunctional chain transfer agent (D') The amount of the agent (D) and the monofunctional chain transfer agent (D') to be used must satisfy the relationship of the following formulas (2) and (3) with respect to 100 parts by mass of the monomer mixture (C).

(In the formulas (2) and (3), a, b and p each represent an integer of 1 or more, and M _p , n _p and W _p represent any polyfunctional chain transfer in the a polyfunctional chain transfer agent (D). Molecular weight, functional group number and amount (parts by mass) of the agent (D _p ), M' _p and W' _p respectively represent any monofunctional chain transfer agent (D' _p ) of the b kinds of monofunctional chain transfer agents (D') Molecular weight and amount (parts by mass)).

When a monofunctional chain transfer agent (D') is used, the amount of the polyfunctional chain transfer agent (D) and the monofunctional chain transfer agent (D') is from the viewpoint of formability and impact resistance of the obtained polymer compound. In view of the above, the above formula (2) must be satisfied. That is, the constant f and the W' of all the monofunctional chain transfer agents (D') used. N0.5/M' (except for the sum of molecular weight and amount (parts by mass) of each of the monofunctional chain transfer agents (D') of W' and M' (hereinafter referred to as "constant f'") In total, it is 0.0015 or more and 0.0045 or less. It is considered that when a W' part by mass of a monofunctional chain transfer agent (D' having a molecular weight of M' is used with respect to 100 parts by mass of the monomer mixture (C), chain transfer of a growing terminal radical in radical polymerization occurs. The functional group is W'/M' mole per 100 parts by mass of the monomer mixture (C). Therefore, the constant f' means the total number of substituent moles of the monofunctional chain transfer agent (D') in which the terminal radical chain transfer is grown when radical polymerization is carried out using 100 parts by mass of the monomer mixture (C). The sum of the constant f and the constant f' means that the chain is generated when the polyfunctional chain transfer agent (D) and the monofunctional chain transfer agent (D') are used together in the radical polymerization of 100 parts by mass of the monomer mixture (C). The total number of functional moles transferred. When the total of the constant f and the constant f' is less than 0.0015, the formability of the obtained polymer compound is lowered, while on the other hand, if it is more than 0.0045, the punching resistance is lowered. The total of the constant f and the constant f' is preferably in the range of 0.0020 to 0.0040, preferably in the range of 0.0025 to 0.0035.

Further, when a monofunctional chain transfer agent (D') is used, the amount of the polyfunctional chain transfer agent (D) and the monofunctional chain transfer agent (D') is used, and the formability and impact resistance of the obtained polymer compound are obtained. From a sexual point of view, the above formula (3) must be satisfied. That is, the ratio of the constants f' and f must be 1 or less. This means that the movement toward the monofunctional chain transfer agent (D') at the end of the free radical polymerization of the radical polymerization is not greater than the movement toward the polyfunctional chain transfer agent (D). Further, the ratio of the constant f' to the constant f is preferably 0.8 or less, preferably 0.5 or less.

The polymerization initiator (E) used in the production method of the present invention has no particular limitation if it can initiate radical polymerization at the polymerization temperature. The system can be exemplified by azobisisobutyronitrile, azobisisovaleronitrile, 1,1-azobis(1-cyclohexanecarbonitrile), 2,2'-azobis(4-methoxy- Azo system such as 2,4-dimethylvaleronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis-2-methylbutyronitrile a compound; 1,1-bis(t-butylperoxy)cyclohexane, monohexylperoxyisopropyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy-hexanoate- 2-ethyl ester, an organic peroxide such as a lauroyl peroxide, a octyl peroxide peroxide, or an isobutyl peroxide. These polymerization initiators (E) may be used singly or in combination of plural kinds.

The 10-hour half-life temperature of the polymerization initiator (E) is 90 Preferably, it is below °C, preferably 80 ° C or less, more preferably 70 ° C or less. When the 10-hour half-life temperature of the polymerization initiator (E) is more than 90 ° C, the proportion of the low molecular weight polymer in the obtained polymer compound increases, which tends to cause mold contamination during molding and a decrease in strength of the molded article.

The amount of the polymerization initiator (E) to be used is preferably in the range of 0.001 to 0.01 parts by mass based on 100 parts by mass of the monomer mixture (C). Further, from the viewpoint of productivity and polymerization stability, it is preferably in the range of 1.0 × 10 ^-6 to 1.0 × 10 ^-4 mol, more preferably 3.0 ×, with respect to the 1 mol monomer mixture (C). 10 ^-5 ~ 7.0 × 10 ^-5 m range. If the amount of the polymerization initiator used in the 1 molar monomer mixture (C) is less than 1.0 × 10 ^-6 moles, the reaction rate is slow and the productivity is low, and the polymerization initiator is used in an amount of more than 1.0. ×10 ^-4 mol has a tendency to become difficult to control by polymerization.

The polymerization temperature of the radical polymerization by the production method of the present invention is preferably 110 to 170 ° C, more preferably 120 to 160 ° C, still more preferably 130 to 150 ° C. When the polymerization temperature is less than 110 ° C, the viscosity of the reaction liquid becomes high, and for mixing, a large power is required. When the polymerization temperature is higher than 170 ° C, the thermal stability of the obtained polymer compound tends to be low.

The polymerization time in the radical polymerization is 0.5 to 4 hours. The range is preferably from 1 to 3 hours, more preferably from 1.5 to 2.5 hours. When the polymerization time is less than 0.5 hours, the amount of the polymerization initiator (E) increases, and the control of the polymerization reaction becomes difficult, and the adjustment of the molecular weight tends to be difficult. Further, when the polymerization time is more than 4 hours, the productivity tends to be low.

High molecular compound obtained by the production method of the present invention The molecular weight distribution is preferably in the range of 1.6 to 1.8. When the molecular weight distribution is less than 1.6, the formability tends to be low, and when it is more than 1.8, the impact resistance tends to be low.

High molecular compound obtained by the production method of the present invention The weight average molecular weight is preferably in the range of 40,000 to 100,000, preferably in the range of 45,000 to 80,000, and more preferably in the range of 50,000 to 60,000.

Polymer compound obtained by the production method of the present invention The material is excellent in transparency, moldability, and impact resistance, and is useful as various molded articles. A molded article excellent in mechanical strength and appearance of various shapes can be obtained by, for example, conventional melt heat molding such as injection molding, compression molding, extrusion molding, or vacuum molding. As a use of molded articles, it is possible to exemplify signs such as billboards, stand signs, wall pillar signs, signboards on doors and windows, roof signboards, display items such as showcases, partitions, storefront displays, etc.; fluorescent lampshades, mood lighting Lighting supplies such as covers, lampshades, ceiling lights, wall lamps, chandeliers, etc.; interiors such as ornaments and mirrors Decorative items; construction parts for doors, vaults, safety windows, partitions, stair panels, balcony panels, roofs for leisure buildings, aircraft windshields, sun visors for drivers, locomotives, jet skis Transport windshield, bus visor, automotive side visor, rear visor, head wing, headlight cover, instrument housing, taillight cover, etc.; transport equipment related parts; audio image sign board, stereo housing, TV protection Electronic machine parts such as covers and vending machines; medical machine parts such as incubators and X-ray machine parts; machine-related parts such as mechanical casings, instrument covers, experimental devices, scales, keyboards, observation windows, etc.; Optical related parts such as light plates, light guiding films, fresnel lenses, lenticular lenses, front plates of various displays, diffusing plates, etc.; traffic-related parts such as road signs, navigation boards, curved mirrors, soundproof walls, etc.; Surface material for interior, film material for mobile phone, film film for marking film, etc.; cover material for washing machine and control panel, top panel of electric cooker, etc. Parts of electrical products; other greenhouse, a large tank, aquarium, clock panel, bathtub, sanitation equipment, hand bags, game accessories, toys, face protection when the splice enclosures.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the invention is not limited by the examples.

[Production of test piece]

By using an injection molding machine (manufactured by Nippon Steel Works Co., Ltd., J75SAV), H1/H2/HV/H3/MH=200/210/230/250/250 °C, and a mold temperature of 60 °C. The polymer compound obtained in the examples and the comparative examples was subjected to injection molding to prepare a test piece. The test piece was used to measure the physical property value of the molded article.

The polymer compounds obtained in Examples 1 to 4 and Comparative Examples 1 to 5 and the physical properties of the molded articles produced by the above were measured by the following methods.

[Weight average molecular weight, molecular weight distribution]

A gel permeation chromatograph equipped with a column (made by Tosoh Corporation, TSKgelSUPERHZM-M and TSKguard column SUPERHZ-H) and a differential refractometer (made by Tosoh Corporation, RI-8020) The weight average molecular weight (Mw) and molecular weight distribution of the polymer compound obtained in the examples and the comparative examples were determined in polystyrene at 40 ° C in tetrahydrofuran solvent, manufactured by Tosoh Corporation (HLC-8020). (Mw/Mn).

[MFR]

The MFR of the polymer compound obtained in the examples and the comparative examples was measured in accordance with JIS K7210 at a temperature of 230 ° C and a load of 37.3 N.

[resistantness]

The test piece of 80 mm × 10 mm × 4 mm produced by using the polymer compound obtained in the examples and the comparative examples was evaluated in accordance with the bending strength measured in accordance with JIS K7203.

[Transmittance]

The test piece was cut from a flat plate having a thickness of 6 mm to have an optical path length of 200 mm, and the light transmittance in an optical path length of 200 mm of light having a wavelength of 550 nm was measured.

Hereinafter, methyl methacrylate is MMA, methyl acrylate is MA, azobisisobutyronitrile is AIBN, n-octyl thiol is n-OM, pentaerythritol tetrathiopropionate is PETP, ethylene glycol thio Ethylene glycol ester EGTG, 1,2,3-propane trithiol is PTT, and ethylene glycol dimethacrylate is EGDMA. In addition, the above reagents are manufactured by Wako Pure Chemical Industries, Ltd.

[Example 1]

In a polymerization reactor equipped with a stirrer, 0.007 parts by mass of AIBN (4.2×10 ^-5 moles) containing the monomer mixture (C) (1 mole part) and the polymerization initiator (E) are continuously supplied as A mixture of 0.66 parts by mass of PETP of the functional chain transfer agent (D) comprising 89 parts by mass (0.87 mole parts) of MMA and 11 parts by mass (0.13 mole parts) of MA. The constant f is 0.0029 under these conditions. The bulk polymerization was carried out under the conditions of a polymerization temperature of 140 ° C and an average residence time of 2 hours, and the polymerization reaction liquid was continuously withdrawn. Next, the reaction mixture withdrawn from the polymerization reactor was heated to 230 ° C and supplied to a biaxial extruder controlled at 260 ° C. The volatile component containing the unreacted monomer as a main component was separated and removed by the biaxial extruder, and the polymer was extruded into a strand shape. The strand was pelletized by a granulator to obtain a particulate polymer compound. The evaluation results of the obtained polymer compound are shown in Table 1.

[Embodiment 2]

A pelletized polymer compound was obtained in the same manner as in Example 1 except that 0.44 parts by mass of EGTG was used instead of PETP in Example 1 as the polyfunctional chain transfer agent (D). Also, under these conditions, the constant f is 0.0030. The evaluation results of the obtained polymer compound are shown in Table 1.

[Example 3]

A pelletized polymer was obtained in the same manner as in Example 1 except that the amount of PETP in Example 1 was changed to 0.52 parts by mass, and 0.13 parts by mass of n-OM was used in combination as a monofunctional chain transfer agent (D'). Compound. Further, under the present conditions, the constant f is 0.0023, the constant f' is 0.0009, and the sum of the constant f and the constant f' is 0.0032. Further, the ratio (f'/f) of the constant f' to the constant f was 0.39. The evaluation results of the obtained polymer compound are shown in Table 1.

[Example 4]

A pelletized polymer compound was obtained in the same manner as in Example 1 except that PETP in Example 1 was used as the polyfunctional chain transfer agent (D) in an amount of 0.22 parts by mass of PTT. Also, under these conditions, the constant f is 0.0027. The evaluation results of the obtained polymer compound are shown in Table 1.

[Comparative Example 1]

A particulate polymer compound was obtained in the same manner as in Example 1 except that 0.44 parts by mass of n-OM was used instead of PETP in the example as the monofunctional chain transfer agent (D'). Further, the constant f' was 0.0030 under the present conditions. The evaluation results of the obtained polymer compound are shown in Table 1.

[Comparative Example 2]

A particulate polymer compound was obtained in the same manner as in Example 1 except that PETP in Example 1 was used as the monofunctional chain transfer agent (D) instead of 0.16 parts by mass of EGTG. Further, the constant f was 0.0011 under the present conditions. The evaluation results of the obtained polymer compound are shown in Table 1.

[Comparative Example 3]

A particulate polymer compound was obtained in the same manner as in Example 1 except that the amount of PETP in Example 1 was changed to 1.1 parts by mass. Also, under these conditions, the constant f is 0.0049. The evaluation results of the obtained polymer compound are shown in Table 1.

[Comparative Example 4]

The same procedure as in Example 1 except that 0.22 parts by mass of EGTG was used instead of PETP in Example 1 as the monofunctional chain transfer agent (D), and 0.35 parts by mass of n-OM was used in combination as the monofunctional chain transfer agent (D'). Ground, a particulate polymer compound is obtained. Further, under the present conditions, the constant f is 0.0015, the constant f' is 0.0024, and the sum of the constant f and the constant f' is 0.0039. Further, the ratio (f'/f) of the constant f' to the constant f is 1.6. The evaluation results of the obtained polymer compound are shown in Table 1.

[Comparative Example 5]

Except using a monomer mixture (C) (1.0005 mol) containing 89 parts by mass (0.87 mole parts) of MMA, 11 parts by mass (0.13 mole parts) of MA, and 0.10 parts by mass (5.0 x 10 ^-4 mole parts) of EGDMA. In the same manner as in Example 1, except that 0.70 parts by mass of EGTG was used instead of PETP as the polyfunctional chain transfer agent (D), a particulate polymer compound was obtained. Also, under these conditions, the constant f is 0.0047. The evaluation results of the obtained polymer compound are shown in Table 1.

It is understood that Comparative Example 1 which is produced only by the monofunctional chain transfer agent (D') and which is different from the present invention exhibits the same MFR as the examples, but has poor bending strength.

In addition, in Comparative Example 2 in which the amount of the polyfunctional chain transfer agent (D) used was less than the range defined by the formula (1), the MFR was greatly lowered and the fluidity was poor as compared with the examples.

In addition, in Comparative Example 3 in which the amount of the polyfunctional chain transfer agent (D) used was larger than the range defined by the formula (1), the MFR was high, but the bending strength was inferior to the examples.

Further, it has been found that the ratio of use of the polyfunctional chain transfer agent (D) and the monofunctional chain transfer agent (D') is not in the comparative example 4 of the formula (3), and the MFR value equivalent to that of the examples is shown, but the bending is performed. Poor strength.

Further, it is understood that the molecular weight of the polyfunctional chain transfer agent (D) is larger than the range defined by the formula (1), and the monomer mixture (C) contains the polyfunctional monomer, and the molecular weight is compared with the examples. Wide distribution, and poor bending strength and light transmittance.

As described above, the polymer compound obtained by the production method of the present invention is excellent in fluidity and impact resistance because both of MFR and bending strength are excellent. In this way, a molded article excellent in mechanical strength and appearance can be obtained by using the polymer compound of the present invention.

Claims (4)

A method for producing a polymer compound, which is a monomer mixture (C) comprising a methacrylate (A) and a vinyl monomer (B) copolymerizable with the methacrylate (A), and 1 A method for producing a radically polymerized polymer compound in the presence of the above polyfunctional chain transfer agent (D), one or more kinds of monofunctional chain transfer agents (D'), and a polymerization initiator (E), characterized in that: The amount of the polyfunctional chain transfer agent (D) and the monofunctional chain transfer agent (D') used in 100 parts by mass of the monomer mixture (C) satisfies the following formulas (2) and (3). Relationship; (In the formulas (2) and (3), a, b, and p each represent an integer of 1 or more, and M _p , n _{p ,} and W _p respectively represent any polyfunctional chain of the a polyfunctional chain transfer agent (D). The molecular weight, the number of functional groups and the amount (parts by mass) of the transfer agent (D _p ), and M' _p and W' _p respectively represent any monofunctional chain transfer agent (D' of the b monofunctional chain transfer agent (D'). The molecular weight and amount (parts by mass) of _p ). The method for producing a polymer compound according to claim 1, wherein the polymerization initiator (E) is used in the range of 0.001 to 0.01 parts by mass. A polymer compound obtained by the production method of claim 1 or 2. A molded article comprising the polymer compound of claim 3.