JP6372565B2 - Method for producing block polymer - Google Patents

Description

  The present invention relates to a method for producing a block polymer in which a monomer having three or more components is polymerized.

  Acrylic polymers can be easily produced by radical polymerization of acrylic monomers, and the properties of the resin can be widely changed by copolymerizing several types of acrylic monomers depending on the purpose. Widely manufactured industrially. Further, bulk polymerization, solution polymerization, suspension polymerization and the like are widely used as the production method, and are selected in view of the molecular weight and cost of the acrylic polymer to be produced. Conventional acrylic polymers are generally produced by free radical polymerization, so acrylic polymers obtained from multi-component monomers are random copolymers and have a broad molecular weight distribution.

  Acrylic polymers can develop characteristics such as transparency, adhesiveness, low elasticity, and high hardness by selecting monomer types, and are being developed in the fields of optics, electronic materials, and structural materials. In addition, by copolymerizing acrylic acid or methacrylic acid as a component thereof, it is provided with a photosensitive resist material by imparting alkali aqueous solubility. Also, by copolymerizing glycidyl methacrylate, it is possible to incorporate a thermosetting reaction or introduce a photoreactive group to incorporate photoreactivity, for example, to increase the heat resistance of the adhesive, It is possible to impart sex.

  In recent years, various living radical polymerizations capable of controlling the structure of block polymers, graft polymers, star polymers and the like have been developed in order to realize high performance and high functionality of acrylic polymers. Reversible addition-fragmentation chain transfer (RAFT) polymerization has been developed as a living radical polymerization method as a method for synthesizing acrylic polymers. RAFT polymerization takes the behavior of living polymerization by using a chain transfer agent having a thiocarbonate structure to cause reversible addition cleavage at the polymer growth terminal and causing chain transfer to a monomer. RAFT polymerization can polymerize acrylic acid and methacrylic acid without protecting groups, and enables copolymerization with various acrylic esters, methacrylic esters, styrene, etc. (see Patent Documents 1 and 2). ).

Special Table 2000-515181 JP 2010-59231 A

In the production method of a multi-component copolymer polymer having three or more components, the present invention can improve the block property of other monomers so that the physical properties of the polymer due to the specific polymerizable monomer do not change due to the sequence of the polymer. It is an object to obtain a possible block polymer.
Among them, the purpose is to produce such a block polymer as an acrylic polymer, and among them, in a multicomponent copolymer of three or more components including acrylic acid or methacrylic acid, structural units other than those derived from acrylic acid or methacrylic acid are used. An object of the present invention is to obtain an acrylic polymer that can be blocked and has properties that do not reduce solvent solubility or solubility in an aqueous alkali solution.

  The present invention relates to a method for producing a block polymer in which a polymerizable monomer having three or more components is polymerized, and a step of obtaining a first polymer unit by polymerizing a first polymerizable monomer and a second polymerizable monomer by living polymerization. A block polymer having a first polymerizable monomer, and then a step B for adding a third polymerizable monomer different from the second polymerizable monomer to chain extend the second polymer unit. It relates to a manufacturing method.

In the present invention, after the step A and the step B, a first polymerizable monomer and a fourth polymerizable monomer different from the third polymerizable monomer are added to chain the third polymer unit. The present invention relates to a method for producing the block polymer having the step C of stretching.
In the present invention, after the step C, the step of chain-extending the n + 1th polymerizable monomer different from the first polymerizable monomer and the immediately preceding nth polymerizable monomer is further repeated one or more steps. The present invention relates to a method for producing a block polymer.

The present invention also relates to a method for producing each block polymer, wherein the first polymerizable monomer is a carboxyl group-containing polymerizable monomer.
Furthermore, the present invention relates to a method for producing each of the block polymers, wherein the second and subsequent polymerizable monomers are acrylic monomers, styrenic monomers or acrylonitrile.

  According to the method for producing a block polymer of the present invention, in a multi-component copolymer polymer having three or more components, the block property of another monomer is controlled so that the physical properties of the polymer due to the specific polymerizable monomer are not changed by the sequence of the polymer. Can be increased. Further, according to the production method of the present invention, it is possible to easily produce a block polymer having acrylic acid or methacrylic acid which is excellent in solubility in a solvent or an alkaline aqueous solution, and the resulting acrylic polymer is a photosensitive resist. It can be suitably applied as an adhesive and a photo-curing resin.

Gel permeation chromatogram at the time of first polymer unit synthesis in Example 1 and after the second polymer unit chain extension 1: Gel permeation chromatogram at the time of first polymer unit synthesis 2: Gel after the second polymer unit chain extension Permeation chromatogram

1H-NMR spectrum during synthesis of the first polymer unit of Example 1: OH signal of methacrylic acid 4: Signal of aromatic ring of styrene

1H-NMR spectrum after chain extension of the second polymer unit of Example 1 5: Signal of OH of methacrylic acid 6: Signal of aromatic ring of styrene and benzyl methacrylate 7: Signal of methylene of benzyl methacrylate

  The production method of the present invention is a production method of a block polymer obtained by polymerizing a polymerizable monomer having three or more components, wherein the first polymerizable monomer and the second polymerizable monomer are polymerized by living polymerization. Step A to obtain a polymer unit of the following, followed by Step B of chain-extending the second polymer unit by adding a first polymerizable monomer and a third polymerizable monomer different from the second polymerizable monomer Have

Further, in the production method of the present invention, after the step A and the step B, a first polymerizable monomer and a fourth polymerizable monomer different from the third polymerizable monomer are added, and the third polymerizable monomer is added. It is possible to have step C of chain extending the polymer unit.
Furthermore, in the production method of the present invention, after the step C, the step of chain-extending the first polymerizable monomer and the (n + 1) th polymerizable monomer different from the immediately preceding nth polymerizable monomer further includes one step. It is possible to repeat the above.

Living polymerization in the present invention includes anionic polymerization, atom transfer radical polymerization (ATRP), nitroxide living radical polymerization (NMP), reversible addition-fragmentation chain transfer (RAFT) polymerization, organic tellurium-mediated living radical polymerization (TERP), reversible. Chain transfer catalytic polymerization (RTCP) or the like can be used.
Living radical polymerization reversibly protects the growing radical in radical polymerization, and the molecular chain is gradually changed by repeating deprotection (activation), addition of monomer (growth), and protection (inactivation) of the protecting group, The polymer grows almost uniformly and a polymer with a narrow molecular weight distribution is obtained. Even if the monomer is depleted from the reaction system, polymerization is started by supplying a new monomer, and chain elongation occurs. Among them, reversible addition-fragmentation chain transfer polymerization (RAFT) using a thioester as a protecting group which is a chain transfer agent is preferable in that it has many polymerizable monomer species and can directly copolymerize acrylic acid or methacrylic acid.

  In this RAFT polymerization, a thiocarbonate compound having a structure represented by the general formula (1) can be used as a chain transfer agent.

（Ｒは、一価の基を示し、Ｚは、一価の基を示す。）

(R represents a monovalent group, and Z represents a monovalent group.)

Here, as R, cumyl group, cyanopropyl group, phenylpropyl group, cyanophenylmethyl group, ethylcarboxypropyl group, 2,4,4-trimethylpentan-2-yl group, 1-cyanoethyl group, 1-phenyl Preferred examples include an ethyl group, a tertiary butyl group, a cyanomethyl group, and a benzyl group.
Z is preferably a phenyl group, a methylthioyl group, a pyrrole group, a methyl group, a phenoxy group, an ethoxy group, a dimethylamino group, or the like.

  Specific examples of these chain transfer agents include cumyl dithiobenzoate, 2-cyano-2-propylbenzothioate, 4-cyano-4 [(dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid, cyanomethylmethyl (phenyl) Carbamodithioate, 4-cyano-4- (phenylcarbonothioylthio) pentanoic acid, 2-cyano-2-propyldodecyltrithiocarbonate, 2- (dodecylthiocarbonothioylthio) -2-methylpropionic acid, Although cyanomethyl dodecyl trithio carbonate etc. are mentioned and these are marketed, it is not limited to these.

In the present invention, the polymerizable monomer includes a monomer having a polymerizable carbon-carbon unsaturated double bond, and specifically includes an acrylic monomer, a styrene monomer, acrylonitrile and the like.
Here, the acrylic monomer refers to a monomer having an acryloyl group (CH═CH—CO—) or a methacryloyl group (CH═C (CH ₃ ) —CO—).

The production method of the present invention is preferably applied to the production of a block polymer of an acrylic polymer (referred to a polymer using the acrylic monomer as a polymerization component) using an acrylic monomer or a styrene monomer as a polymerizable monomer.
In the present invention, the first polymerizable monomer is not particularly limited, and examples thereof include a carboxyl group-containing monomer, among which acrylic acid, methacrylic acid and the like are preferable.

  Further, the second polymerizable monomer, the third polymerizable monomer, the fourth, fifth, sixth,... Polymerizable monomer (that is, the (n + 1) th polymerizable monomer different from the nth polymerizable monomer. ) May be preferably acrylic monomers, styrene monomers, acrylonitrile, etc. other than the first polymerizable monomer.

Among these, as a combination of monomers suitable to be obtained by the production method of the present invention, the first polymerizable monomer; (meth) acrylic acid, the second and subsequent monomers; styrene, (meth) acrylic acid benzyl, (meth) Examples thereof include methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate, and the like.
((Meth) acrylic acid OO means acrylic acid XX or methacrylic acid XX.)

  In the present invention, the first polymerizable monomer (for example, acrylic acid or methacrylic acid) and the second polymerizable monomer are living polymerized using the thiocarbonate compound having the structure represented by the general formula (1) as a chain transfer agent. The first polymer unit is synthesized by polymerization, and when the polymerization has progressed to some extent, the polymer to be the first polymer unit is recovered by reprecipitation or distillation under reduced pressure, and then the first polymerizable monomer and By adding with the three polymerizable monomers, the second polymer unit can be chain extended. In this case, a small amount of radical initiator may be added.

  In addition, a thiocarbonate compound having a structure represented by the general formula (1) is used as a chain transfer agent, and a first polymer unit and a second polymerizable monomer are polymerized by living polymerization to synthesize a first polymer unit. When the polymerization has progressed to some extent, the first polymer monomer and the third polymer monomer are added to the same reactor, and the second polymer unit is chain-extended to obtain the block polymer of the present invention. be able to.

  The first polymerizable monomer used first, the second monomer polymerizable with this, the first polymerizable monomer charged later, the third monomer polymerizable with this, and the molar amount and the general formula ( By controlling the molar ratio of the thiocarbonate compound represented by 1), the molecular weight of the resulting block polymer, the molecular weight of the first polymer unit (chain length), and the molecular weight of the second polymer unit (chain length) It is possible to adjust.

  Generally, the molar ratio of the serial transfer agent, specifically the compound represented by the general formula (1), and the radical initiator is preferably 20/1 to 1/5, and more preferably 10/1 to 1/4. The ratio of the compound represented by the general formula (1) to the radical initiator is 20/1 or less, which is industrially preferable because the polymerization reaction rate can be increased while maintaining monodispersity. By setting the number to 5 or more, chain transfer from the radical initiator directly to the monomer can be avoided, and the random polymer different from the block polymer of the present invention, the first polymer unit alone, and the second polymer unit alone It is possible to obtain a good block polymer by suppressing the by-production of the polymer.

  The temperature of the polymerization reaction varies depending on the decomposition temperature of the radical initiator to be used, and is not particularly limited, but it is generally preferable to carry out at a half-life decomposition temperature of minus 2 ° C. to plus 20 ° C. By controlling the temperature within this range with respect to the half-life decomposition temperature, it is possible to reduce the molecular weight distribution, and it is possible to suppress a decrease in blocking due to a by-product of a polymer having no structure of the general formula (1).

  Radical initiators for synthesizing the block polymers of the present invention include peroxides such as benzoyl peroxide, acetyl peroxide, lauroyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, and dicumyl peroxide. Examples thereof include oxide initiators, azo initiators such as AIBN (2,2′-azobisisobutyronitrile), V-65 (azobisdimethylvaleronitrile), and the like. Of these, AIBN (2,2'-azobisisobutyronitrile) is preferable.

  The block polymer of the present invention can be synthesized by solution polymerization, suspension polymerization, emulsion polymerization, solid phase polymerization, etc., but solution polymerization may be used to obtain a resin having a weight average molecular weight of 2,000 to 300,000. Preferably, suspension polymerization is preferred to obtain a resin having a weight average molecular weight of 300,000 to 1,000,000. The polymerization method is appropriately selected depending on the polarity and reactivity of the monomer used, but when acrylic acid or methacrylic acid is used, solution polymerization may be performed to synthesize an acrylic polymer that is soluble in a solvent from the viewpoint of its solubility. preferable.

  Although there is no restriction | limiting in particular in the molecular weight of the block polymer manufactured by this invention, Generally 10,000-200,000 are preferable at a weight average molecular weight. In general, the molecular dispersity is preferably 1.2 to 4.0. In addition, molecular weight can be calculated | required by measuring by a gel permeation chromatography method and converting using a standard polystyrene calibration curve.

Solution polymerization is performed by dissolving a polymerizable monomer, a chain transfer agent, a radical initiator, and a resin to be produced in a solvent that can be dissolved, and then heating to a temperature determined by the radical initiator. At this time, it is possible to carry out the polymerization under air, but it is preferred to carry out under nitrogen.
The solvent used in the solution polymerization is not particularly limited as long as it can dissolve a polymerizable monomer, a chain transfer agent, a radical initiator, and a resin to be formed, but preferably has a boiling point equal to or higher than the temperature at which the polymerization is performed. When the temperature at which the polymerization is carried out is higher than the boiling point of the solvent used, the polymerization can be carried out by a reaction under pressure.

  As the organic solvent to be used, methoxyethanol, ethoxyethanol, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanol, cyclohexanone, butyl acetate, chlorobenzene, dioxane, propylene glycol monomethyl ether and the like are used, and are not particularly limited. These can be used alone or in combination.

  In RAFT polymerization, there is generally no chain transfer from the acrylic growth end to the methacrylate monomer. Therefore, the monomer blending procedure and combination when copolymerizing a plurality of monomers are important. Therefore, when simultaneously charging a plurality of monomers, it is preferable to carry out a combination of only monomers having an acryloyl group or only a monomer having a methacryloyl group.

  In the present invention, in order to grow a polymer stepwise by block polymerization, polymerization is performed with a combination of monomers having an acryloyl group alone, or after polymerization of a monomer having a methacryloyl group with a combination of monomers only having a methacryloyl group. It is preferable to polymerize a monomer having an acryloyl group.

  The block polymer obtained by the present invention is expected to exhibit excellent properties in applications such as photosensitive materials, adhesives, pressure-sensitive adhesives, coating materials, and dispersants.

Examples are described below, but the present invention is not limited to these examples.
Example 1
In a 500 ml separable flask equipped with a reflux condenser, a thermometer, a stirrer, and a nitrogen introduction tube, 25.0 g (290 mmol) of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.), styrene monomer (manufactured by Wako Pure Chemical Industries, Ltd.) 67.5 g (648 mmol), cumyl dithiobenzoate 1.46 g (5.36 mmol), azobisisobutyronitrile (Wako Pure Chemical Industries, Ltd., purity 98%) 0.45 g (2.73 mmol) were charged at room temperature. Nitrogen was bubbled and stirred for 30 minutes. The temperature was raised to 65 ° C. and stirred for 30 minutes, after which the temperature was raised to 70 ° C. When the viscosity of the reaction solution increased, 46 g of a toluene / propylene glycol monomethyl ether (2/3 weight ratio) mixed solution in which nitrogen was bubbled for 30 minutes was added and further stirred. The mixture was stirred at 80 ° C. for 2 hours, and the solid content and molecular weight were measured. The polymerization rate calculated from the solid content was 94%, the weight average molecular weight (Mw) of the styrene / methacrylic acid unit was 12,900, and the number average molecular weight (Mn) was 9,200. To this reaction solution, 15.5 g (181 mmol) of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.) and 42.0 g (238 mmol) of benzyl methacrylate (funcryl FA-BZM manufactured by Hitachi Chemical Co., Ltd.) were added and further stirred at 70 ° C. Continued. When the viscosity of the reaction solution increased, 46 g of a toluene / propylene glycol monomethyl ether (2/3 weight ratio) mixed solution in which nitrogen was bubbled for 30 minutes was added and further stirred. The mixture was stirred at 80 ° C. for 4 hours, and the solid content and molecular weight were measured. After completion of the reaction, a mixed solution of acrylic polymer in toluene / propylene glycol monomethyl ether (2/3 weight ratio) was obtained. The weight average molecular weight (Mw) of the obtained polymer was 21,900, the number average molecular weight (Mn) was 15,100, and the solid content of the varnish was 34% by mass.

(Example 2)
In a 500 ml separable flask equipped with a reflux condenser, a thermometer, a stirrer, and a nitrogen introduction tube, 25.0 g (290 mmol) of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.), styrene monomer (manufactured by Wako Pure Chemical Industries, Ltd.) 67.5 g (648 mmol), cumyl dithiobenzoate 0.68 g (2.5 mmol), azobisisobutyronitrile (Wako Pure Chemical Industries, Ltd., purity 98%) 0.21 g (1.28 mmol) were charged at room temperature. Nitrogen was bubbled and stirred for 30 minutes. The temperature was raised to 65 ° C. and stirred for 30 minutes, after which the temperature was raised to 70 ° C. When the viscosity of the reaction solution increased, 46 g of a toluene / propylene glycol monomethyl ether (2/3 weight ratio) mixed solution in which nitrogen was bubbled for 30 minutes was added and further stirred. The mixture was stirred at 80 ° C. for 2 hours, and the solid content and molecular weight were measured. The polymerization rate calculated from the solid content was 92%, the weight average molecular weight (Mw) of the styrene / methacrylic acid unit was 21,400, and the number average molecular weight (Mn) was 16,900. To this reaction solution, 15.5 g (181 mmol) of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.) and 42.0 g (238 mmol) of benzyl methacrylate (funcryl FA-BZM manufactured by Hitachi Chemical Co., Ltd.) were added and further stirred at 70 ° C. Continued. When the viscosity of the reaction solution increased, 46 g of a toluene / propylene glycol monomethyl ether (2/3 weight ratio) mixed solution in which nitrogen was bubbled for 30 minutes was added and further stirred. The mixture was stirred at 80 ° C. for 4 hours, and the solid content and molecular weight were measured. After completion of the reaction, a mixed solution of acrylic polymer in toluene / propylene glycol monomethyl ether (2/3 weight ratio) was obtained. The weight average molecular weight (Mw) of the obtained polymer was 40,300, the number average molecular weight (Mn) was 32,000, and the solid content of the varnish was 34% by mass.

(Example 3)
In a 500 ml separable flask equipped with a reflux condenser, a thermometer, a stirrer, and a nitrogen introduction tube, 25.0 g (290 mmol) of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.), styrene monomer (manufactured by Wako Pure Chemical Industries, Ltd.) 67.5 g (648 mmol), cumyl dithiobenzoate 1.12 g (4.1 mmol), azobisisobutyronitrile (Wako Pure Chemical Industries, Ltd., purity 98%) 0.17 g (1.01 mmol) were charged at room temperature. Nitrogen was bubbled and stirred for 30 minutes. The temperature was raised to 65 ° C. and stirred for 30 minutes, after which the temperature was raised to 70 ° C. When the viscosity of the reaction solution increased, 46 g of a toluene / propylene glycol monomethyl ether (2/3 weight ratio) mixed solution in which nitrogen was bubbled for 30 minutes was added and further stirred. The mixture was stirred at 80 ° C. for 2 hours, and the solid content and molecular weight were measured. The polymerization rate calculated from the solid content was 92%, the weight average molecular weight (Mw) of the styrene / methacrylic acid unit was 11,300, and the number average molecular weight (Mn) was 9,000. After cooling to room temperature, the reaction solution was reprecipitated with hexane and vacuum dried at 40 ° C. 50.0 g of the obtained solid, 46 g of toluene / propylene glycol monomethyl ether (2/3 weight ratio) mixed solution, 8.4 g (97.6 mmol) of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.), benzyl methacrylate (Hitachi Chemical) 22.7 g (128.8 mmol) of FANCLIL FA-BZM manufactured by Corporation was added and stirred. After the solid matter was dissolved, the temperature was raised to 70 ° C. and stirred. When the viscosity of the reaction solution increased, 46 g of a toluene / propylene glycol monomethyl ether (2/3 weight ratio) mixed solution in which nitrogen was bubbled for 30 minutes was added and further stirred. The mixture was stirred at 80 ° C. for 2 hours, and the solid content and molecular weight were measured. After completion of the reaction, a mixed solution of acrylic polymer in toluene / propylene glycol monomethyl ether (2/3 weight ratio) was obtained. The weight average molecular weight (Mw) of the final acrylic polymer including the units of methacrylic acid / benzyl methacrylate was 30,500, the number average molecular weight (Mn) was 23,800, and the solid content of the varnish was 34% by mass.

(Examples 4 to 6)
According to Example 1, an acrylic polymer was obtained with a combination of a monomer and a RAFT agent shown in the following table.

(Comparative Example 1)
In a 500 ml separable flask equipped with a reflux condenser, thermometer, stirrer, and nitrogen inlet tube, 63.0 g (605 mmol) of styrene monomer (manufactured by Wako Pure Chemical Industries, Ltd.), benzyl methacrylate (funkrill manufactured by Hitachi Chemical Co., Ltd.) FA-BZM) 39.2 g (222 mmol), cumyl dithiobenzoate 1.34 g (4.93 mmol), azobisisobutyronitrile (Wako Pure Chemical Industries, Ltd., purity 98%) 0.184 g (1.10 mmol) Charged and bubbled nitrogen at room temperature and stirred for 30 minutes. The temperature was raised to 65 ° C. and stirred for 30 minutes, then the temperature was raised to 70 ° C. and stirred for 2 hours, and further stirred at 80 ° C. for 2 hours, and the solid content and molecular weight were measured. The polymerization rate calculated from the solid content was 96%, the weight average molecular weight (Mw) of the styrene / benzyl methacrylate unit was 14,100, and the number average molecular weight (Mn) was 11,300. To this reaction solution, 37.8 g (439 mmol ) of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd. ) and 46 g of a mixed solution of toluene / propylene glycol monomethyl ether (2/3 weight ratio) were added, and stirring was continued at 70 ° C. When the viscosity of the reaction solution increased, 46 g of propylene glycol monomethyl ether that had been bubbled with nitrogen for 30 minutes was added and further stirred. The mixture was stirred at 80 ° C. for 4 hours, and the solid content and molecular weight were measured. After completion of the reaction, a mixed solution of acrylic polymer in toluene / propylene glycol monomethyl ether (2/3 weight ratio) was obtained. The weight average molecular weight (Mw) of the obtained polymer was 20,900, the number average molecular weight (Mn) was 16,000, and the solid content of the varnish was 34% by mass.

(Comparative Example 2)
According to Comparative Example 1, an acrylic polymer having benzyl methacrylate and styrene as block units was obtained.

(Reference Example 1)
In a 500 ml separable flask equipped with a reflux condenser, a thermometer, a stirrer, and a nitrogen introduction tube, 45.0 g (432 mmol) of styrene monomer (made by Wako Pure Chemical Industries, Ltd.), methacrylic acid (made by Wako Pure Chemical Industries, Ltd.) 27.0 g (314 mmol), benzyl methacrylate (Hankuri Chemical Co., Ltd., fanacrylyl FA-BZM) 28.0 g (159 mmol), cumyl dithiobenzoate 1.24 g (4.55 mmol), azobisisobutyronitrile (sum) Mitsui Chemicals, Inc., purity 98%) 0.15 g (0.88 mmol) was charged, nitrogen was bubbled at room temperature, and the mixture was stirred for 30 minutes. The temperature was raised to 65 ° C. and stirred for 30 minutes, and then the temperature was raised to 70 ° C. and stirred for 2 hours. When the viscosity of the reaction solution increased, 46 g of propylene glycol monomethyl ether that had been bubbled with nitrogen for 30 minutes was further added. Stir. Furthermore, it stirred at 80 degreeC for 4 hours, and measured solid content and molecular weight. The polymerization rate calculated from the solid content was 96%. After completion of the reaction, a mixed solution of acrylic polymer in toluene / propylene glycol monomethyl ether (2/3 weight ratio) was obtained. The weight average molecular weight (Mw) of the obtained polymer was 24,500, the number average molecular weight (Mn) was 25,400, and the solid content of the varnish was 34% by mass.

[Evaluation]
The reaction solution and the obtained acrylic polymer were evaluated according to the following.
[Measurement of Solid Content and Reaction Rate] The solid content of the reaction solution or acrylic polymer varnish was accurately weighed in an aluminum petri dish that had been weighed and heated at 150 ° C. for 15 minutes, and then weighed again to obtain the following formula. .
Solid content (%) = [weight after heating (g) −weight of aluminum petri dish (g)] / weight of acrylic polymer varnish (g) × 100
Reaction rate (%) = solid content (%) / [total charged acrylic monomer (g) / total charged amount (g) × 100]

[Measurement of molecular weight]
The number average molecular weight (Mn), weight average molecular weight (Mw), and Mw / Mn of the acrylic polymers of Examples and Comparative Examples were measured by GPC (gel permeation chromatography) by measuring the chromatogram of the molecular weight distribution of the acrylic polymer. It calculated | required in conversion from the elution time of the standard polystyrene in 25 degreeC. In addition, the measurement apparatus uses Tosoh Co., Ltd. EcoSEC, HLC-8320GPC, and GPC as an eluent, tetrahydrofuran is used, and the columns are Gelpack GL-A-150, Gelpack GL-A-10 (Hitachi High-Technologies Corporation) (Product name) was directly connected.

[Monomer composition analysis of acrylic polymer]
The monomer compositions of the acrylic polymers of the examples and comparative examples were determined by nuclear magnetic resonance spectra (NMR).
[Evaluation results]

Claims (3)

A method for producing a block polymer that polymerizes a polymerizable monomer of three or more components, wherein the first polymer unit and the second polymerizable monomer are polymerized by living polymerization to obtain a first polymer unit; and Thereafter, a first polymerizable monomer, and a step B for chain-extending the second polymer unit by adding a third polymerizable monomer different from the second polymerizable monomer ,
The first polymerizable monomer is a carboxyl group-containing polymerizable monomer,
The method for producing a block polymer, wherein the second and subsequent polymerizable monomers are benzyl (meth) acrylate, propyl (meth) acrylate, lauryl (meth) acrylate, styrene monomer or acrylonitrile .   After the step A and the step B, a step C of chain-extending the third polymer unit by further adding a first polymerizable monomer and a fourth polymerizable monomer different from the third polymerizable monomer. The method for producing a block polymer according to claim 1. After the step C, the step of adding the first polymerizable monomer and the ( n + 1 ) th polymerizable monomer to chain-extend the nth polymer unit (n is an integer of 4 or more) is further repeated one or more steps. return to, polymerizable monomer of the (n + 1) is the production of different block polymers of claim 2, wherein the polymerizable monomer of the n the polymeric units are added in the step of chain extension of the (n-1) Method.

Images