JP6801223B2 - A method for producing a macromonomer copolymer and a method for producing a molded product using the same. - Google Patents

Description

The present invention relates to an isobornyl (meth) acrylate resin composition, a (meth) acrylate resin composition, a butyl acrylate resin composition, a heat-resistant resin, and a molded product.

Acrylic resins are widely used in optical media, automobile parts, building materials, etc. due to their excellent transparency, workability, surface hardness, light resistance, and the like. However, acrylic resins have low heat resistance and are insufficient in applications such as automobile headlamps.
In Non-Patent Document 1, the glass transition temperature is improved by randomly copolymerizing methyl (meth) acrylate and isobornyl (meth) acrylate. However, in Non-Patent Document 1, it cannot be said that the processability is sufficiently high because the resin molding temperature is high. Further, in Non-Patent Document 2, a film is produced by random copolymerization of isobornyl (meth) acrylate and butyl acrylate. In Non-Patent Document 2, since the thermal decomposition temperature starts from around 200 ° C., it cannot be said that the heat resistance is sufficiently high. For this reason, the acrylic copolymer has a problem in achieving both heat resistance and process moldability.

Macromolecules 1995, 28, 6488-6493. Optical Materials 2014, 36, 804-808.

An object of the present invention is to propose an acrylic resin composition capable of reducing the occurrence of molding defects when processing and molding an acrylic copolymer, and obtaining good optical properties and heat resistance.

[1] A (meth) acrylic macromonomer (A) having a glass transition temperature of 115 to 165 ° C. (A) 50 to 90 wt% and a (meth) acrylic acid ester (B) having a glass transition temperature of 0 ° C. to -60 ° C. A method for producing a polymer that copolymerizes with 10 to 50 wt%.
[2] The method for producing a polymer according to [1], wherein the (meth) acrylic macromonomer (A) is a macromonomer having the following structural formula.
[3] Production of the polymer according to [1] or [2], wherein 0 to 45 wt% of the (meth) acrylic acid ester (C) having a glass transition temperature of 100 ° C. or higher is further copolymerized at the time of the copolymerization. Method.
[4] The method for producing a polymer according to any one of [1] to [3], wherein the copolymerization is a solution polymerization method.
[5] The method for producing a polymer according to [4], wherein the solvent used in the solution polymerization method is toluene or dimethylacetamide.
[6] The macromonomer (A) has a number average molecular weight (Mn) of 1000 to 30000 as measured by GPC using a calibration curve using polymethylmethacrylate as a standard substance, whichever is [1] to [5]. The method for producing a polymer according to the above.
[7] A resin molded product obtained by molding the polymer according to any one of [1] to [4].

Since the macromonomer copolymer of the present invention can reduce the occurrence of molding defects of the heat-resistant acrylic resin and can obtain good (optical characteristics and) heat resistance, it is possible to obtain electric / electronic / OA equipment and electric / electronic / OA equipment. It is suitable for housings, optical media, automobile parts, automobile interior materials, building materials, automobile headlamps, seats and the like.

<(Meta) acrylic macromonomer (A)>
The number average molecular weight (Mn) of the (meth) acrylic macromonomer (A) is 1000 to 30000, more preferably 15000 to 28000, and most preferably 18000 to 26000. When the number average molecular weight is 10,000 or more, the vicut softening temperature of the molded product is excellent, and when it is 30,000 or less, the molding defect tends to be improved.

The macromonomer (A) can contain an isobornyl (meth) acrylate unit (a1) and a methyl methacrylate unit (a2). Further, acrylate (a3) may be contained from the viewpoint of suppressing thermal decomposition of the macromonomer (A), and for example, methacrylates such as ethyl methacrylate, butyl methacrylate, propyl methacrylate and 2-ethylhexyl methacrylate; methyl acrylate, ethyl acrylate and butyl. Examples thereof include acrylates such as acrylate, propyl acrylate, 2-ethylhexyl acrylate and glycidyl acrylate. Of these, methacrylate is preferable because it has excellent copolymerizability. One of these monomers may be used alone, or two or more of these monomers may be used in combination.

The total amount of the isobornyl (meth) acrylate unit (a1), the methyl methacrylate unit (a2), and the other monomer (a3) is 100 wt%, whereas the amount of the other monomer (a3) is preferably 5 wt% or less. When the content of the other monomer (a3) is 5 wt% or less, the heat-resistant decomposition property of the obtained molded product tends to be excellent.

Examples of the method for producing the macromonomer (A) include known suspension polymerization, solution polymerization, emulsion polymerization, bulk polymerization and the like. Suspension polymerization is preferable because the recovery method is easy.

<Isobornyl (meth) acrylate unit (a1)>
The isobornyl (meth) acrylate unit (a1) is a component contained in the acrylic resin composition of the present invention.

The isobornyl (meth) acrylate unit (a1) contained in the macromonomer (A) in the acrylic resin composition is 10 wt% or more in a total of 100 wt% of the isobornyl (meth) acrylate unit (a1) and the methyl methacrylate unit (a2). It is preferably 30 wt% or more, and more preferably 70 wt% or more. When the isobornyl (meth) acrylate unit (a1) is 70 wt% or more, the Vicut softening temperature and optical characteristics of the obtained molded product tend to be excellent.

<Methyl methacrylate unit (a2)>
The methyl methacrylate unit (a2) is a component contained in the acrylic resin composition of the present invention.

The methyl methacrylate unit (a2) contained in the macromonomer (A) in the acrylic resin composition is 90 wt% or less in a total of 100 wt% of the isobornyl (meth) acrylate unit (a1) and the methyl methacrylate unit (a2). It is preferably 70 wt% or less, and more preferably 30 wt% or less. When the methyl methacrylate unit (a2) is 30 wt% or less, the Vicut softening temperature and optical characteristics of the obtained molded product tend to be excellent.

<Acrylic acid ester (B)>
The acrylic acid ester (B) of the present invention is a component contained in the acrylic resin composition of the present invention.

The acrylic acid ester (B) is an acrylate having a homopolymer glass transition temperature of 0 ° C. to −60 ° C. For example, acrylates such as ethyl acrylate, butyl acrylate, propyl acrylate, 2-ethylhexyl acrylate and glycidyl acrylate can be mentioned. Of these, butyl acrylate is preferable because it has excellent copolymerizability.

The acrylic acid ester (B) contained in the acrylic resin composition contains 10 to 50 wt% of the acrylic acid ester (B) with respect to 100 wt% of the total of the macromonomer (A) and the acrylic acid ester (B). More preferably, it is 10 to 45 wt%. When the acrylic acid ester (B) is 50 wt% or more, the heat resistance tends to decrease, and when it is 10 wt% or less, the moldability tends to decrease, or the viscosity of the reaction solution increases and the polymerization does not proceed. is there.

<(Meta) acrylic acid ester (C)>
The (meth) acrylic acid ester (C) is contained in the acrylic resin composition and is a methacrylate component other than the macromonomer (A).

The (meth) acrylic acid ester (C) is a metal acrylate having a homopolymer glass transition temperature of 100 ° C. or higher. For example, methacrylates such as methyl methacrylate, t-butyl methacrylate, isobornyl methacrylate, and adamantyl methacrylate can be mentioned. Of these, methyl methacrylate is preferable because it is excellent in moldability and transparency.

The (meth) acrylic acid ester (C) contained in the acrylic resin composition is (meth) based on 100 wt% of the total of macromonomer (A), acrylic acid ester (B) and (meth) acrylic acid ester (C). ) Acrylic acid ester (C) is 0 to 45 wt%. More preferably, it is 0 to 40 wt%. When the (meth) acrylic acid ester (C) is 45 wt% or more, the moldability tends to decrease, and when it is 45 wt% or less, the heat resistance of the molded product tends to improve.

<Macromonomer copolymer>
The macromonomer copolymer is a copolymer of macromonomer (A) and acrylic acid ester (B) and (meth) acrylic acid ester (C), and is an acrylic resin composition.

<Acrylic resin composition>
The acrylic resin composition of the present invention is a macromonomer copolymer having heat resistance. In the present invention, the processability of the acrylic resin composition is improved by copolymerizing a macromonomer having a glass transition temperature of 115 to 165 ° C. and an acrylic acid ester having a glass transition temperature of 0 to -60 ° C. be able to.

<Molded body>
As a method for obtaining a molded product of the present invention, the acrylic resin composition is obtained by molding by a method such as compact molding, hot pressing, injection molding, extrusion molding, or compression molding. Among these, small molding, hot pressing, injection molding, and extrusion molding are preferable because they can be molded into a desired shape.

Hereinafter, the present invention will be described with reference to Examples. The molded product was evaluated by the following method.

(A) Evaluation of workability The following are the molding temperature and the shape of the obtained molded piece when a molded product of 20 mm × 10 mm × thickness 2 mm was produced with a small molding machine (manufactured by Imoto Seisakusho, model number: IMC-18D7). It was judged as follows.
◯: A molded piece having a shape in which the resin is completely filled in the mold can be obtained at a molding temperature of 220 ° C. or lower. ×: A shape in which the resin is completely filled in the mold unless the molding temperature exceeds 220 ° C. Molded pieces cannot be obtained

(B) Evaluation of the degree of transparency A molded product having a size of 20 mm × 10 mm × thickness 2 mm produced by a small molding machine was placed on a color printed matter, and the degree of interpretation and the presence or absence of a change in color tone were judged as follows.
◯: The print can be read and there is no change in color tone △: The print can be read but there is a change in color tone ×: Whitening and the print cannot be read

(C) Measurement of softening temperature (VICAT) The softening temperature of a 20 mm × 10 mm × 2 mm thick molded product was measured according to JIS K7206-A50 (ISO 306).
◯: VICAT softening temperature is 105 ° C. or higher Δ: VICAT softening temperature is 100 ° C. or higher and lower than 105 ° C. ×: VICAT softening temperature is lower than 100 ° C.

(Production Example 1) Synthesis of an aqueous solution of anionic polymer compound (X1) In a polymerization apparatus equipped with a stirrer, 58 parts by mass of 2-sulfoethyl sodium methacrylate and 31 parts by mass of an aqueous potassium methacrylate solution (potassium methacrylate content 30% by mass). A monomer mixture consisting of 11 parts by mass of methyl methacrylate and 900 parts by mass of deionized water were added and dissolved by stirring. Then, the mixture was heated to 60 ° C. with stirring under a nitrogen atmosphere and kept at 60 ° C. with stirring for 6 hours to obtain an aqueous solution of an anionic polymer compound. At this time, after the temperature reached 50 ° C., 0.1 part by mass of ammonium persulfate was added as a polymerization initiator, and 11 parts by mass of methyl methacrylate, which was separately weighed, was continuously added to the above reaction system over 75 minutes. To obtain an aqueous solution of an anionic polymer compound (X1).

(Production Example 2) Synthesis of anionic polymer compound aqueous solution (X2) A simple polymer consisting of 100 parts by mass of an aqueous potassium methacrylate solution (30% by mass of potassium methacrylate) and 70 parts by mass of methyl methacrylate in a polymerization apparatus equipped with a stirrer. The mixture was added and stirred, and after the polymerization peak appeared, the mixture was cooled to obtain an anionic polymer compound aqueous solution (X2).

(Production Example 3) Synthesis of macromonomer (A) Acryester IBX (isobornyl methacrylate manufactured by Mitsubishi Rayon Co., Ltd., trade name) and Acryester M (trade name) are placed in a reaction vessel equipped with a stirrer, a cooling tube and a thermometer. A total of 100 parts by mass of methyl methacrylate (trade name) manufactured by Mitsubishi Rayon Co., Ltd. and 145 parts by mass of deionized water, 0.1 part by mass of sodium sulfate (Na ₂ SO ₄ ) as a dispersion stabilizer, and perocta as a polymerization initiator. 0.4 parts by mass of O (manufactured by Nichiyu Co., Ltd., trade name) and 12 ppm of cobalt complex were added and dissolved by stirring. Next, 0.48 parts by mass of the anionic polymer compound aqueous solution (X1) and 0.04 parts by mass of the anionic polymer compound aqueous solution (X2) were added to sufficiently replace the inside of the polymerization apparatus with nitrogen, and 80 parts of the aqueous dispersion was added. After the temperature was raised to ° C. and held for 3 hours, the temperature was raised to 90 ° C. and held for 1 hour. Then, the reaction solution was cooled to 40 ° C. to obtain an aqueous suspension of macromonomer (A). The aqueous suspension was filtered through a filter cloth, the filtrate was washed with deionized water and dried at 80 ° C. for 18 hours to give the macromonomer (A).

(Production Example 4) Synthesis of macromonomer copolymer (A-1) Macromonomer (A) produced in Production Example 1 and butyl acrylate (Mitsubishi Chemical Corporation) were placed in a polymerization apparatus equipped with a stirrer and a cooling tube. ), Acryester M (manufactured by Mitsubishi Rayon Co., Ltd., methyl methacrylate, trade name), toluene was added as a solvent so that the monomer concentration was 50% by weight, the temperature was raised to 45 ° C., and the mixture was stirred for 30 minutes to make it uniform. Solution. Next, the reaction solution was cooled to room temperature, and the inside of the polymerization apparatus was sufficiently replaced with nitrogen. As a polymerization initiator, 1500 ppm of AIBN (manufactured by Wako Pure Chemical Industries, Ltd., 2,2-azobis-2-methylpropionitrile, trade name) was added, and the reaction solution was heated to 80 ° C. and held for 6 hours. Then, the reaction solution was cooled to room temperature to obtain a syrup of the polymer (A-1). The syrup was reprecipitated with methanol, filtered through a filter cloth, the filtrate washed with methanol and dried at 80 ° C. for 18 hours to give the macromonomer copolymer (A-1).

(Production Example 5) Synthesis of Random Copolymer (A-2) In a polymerization apparatus equipped with a stirrer and a cooling tube, Acryester IBX (isobornyl methacrylate manufactured by Mitsubishi Rayon Co., Ltd., trade name) and Acryester M (Methyl methacrylate manufactured by Mitsubishi Rayon Co., Ltd., trade name), 1-octanethiol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 1000 ppm as a chain transfer agent, and toluene as a solvent was added so that the monomer concentration was 50 wt%. AIBN (manufactured by Wako Pure Chemical Industries, Ltd., 2,2-azobis-2-methylpropionitrile, trade name) was added at 1500 ppm, and the reaction solution was heated to 80 ° C. and held for 6 hours. Then, the reaction solution was cooled to room temperature to obtain a syrup of the polymer (A-1). The syrup was reprecipitated with methanol, filtered through a filter cloth, the filtrate washed with methanol and dried at 80 ° C. for 18 hours to give a random copolymer (A-2).

(Production Example 6) Synthesis of Random Copolymer (A-3) Random polymer (Production Example 6) was operated in the same manner as in Production Example 3 except that butyl acrylate (manufactured by Mitsubishi Chemical Corporation) was added to the copolymer component. A-3) was obtained.

(Example 1)
The operation of Production Example 3 was carried out with the monomer composition shown in Table 1 to prepare a macromonomer (A). The amount of the produced macromonomer (A) added was 56 wt%, the amount of butyl acrylate added was 44 wt%, and the same operation as in Production Example 4 was performed to obtain a small molding machine (manufactured by Imoto Seisakusho, model number: IMC-18D7). It was used to obtain a macromonomer copolymer (A-1).
The polymer (A-1) was molded at a molding temperature of 220 ° C., a kneading speed of 50 rpm, and a kneading time of 1 minute to obtain a molded product having a size of 20 mm × 10 mm × thickness of 2 mm. The evaluation results are shown in Table 1. It could be molded at 220 ° C., which is lower than the thermal decomposition temperature of isobornyl methacrylate, had good transparency of the molded product, and had a high bicut softening point of 115.0 ° C. and had heat resistance.

(Examples 2 to 6)
The macromonomer (A) was prepared in the same manner as in Production Example 3 except that the monomer composition was changed, and the same as in Example 1 except that the addition amounts of the macromonomer (A), butyl acrylate, and methyl methacrylate were changed. Was performed. The evaluation results are shown in Table 1. All of them could be molded at 220 ° C., which is lower than the thermal decomposition temperature of isobornyl methacrylate, and the transparency of the molded product was also good.

(Comparative Example 1)
30 wt% of Acryester IBX and 70 wt% of Acryester M were added, and the same operation as in Production Example 5 was carried out to obtain a random copolymer (A-2). A molded product of the above random copolymer (A-2) was obtained in the same manner as in Example 1. The evaluation results are shown in Table 2. The glass transition temperature of the copolymer was 135 degrees, and the vicut softening temperature of the molded product was 108.4 degrees, showing good heat resistance, but the resin fluidity was low, which is the thermal decomposition temperature of polyisobornyl methacrylate 250. ° C was required as the molding temperature.

(Comparative Example 2)
39 wt% of Acryester IBX, 17 wt% of Acryester M, and 44 wt% of butyl acrylate were added, and the same operation as in Production Example 6 was carried out to obtain a random copolymer (A-3). A molded product of the above random copolymer (A-3) was obtained in the same manner as in Example 1. The evaluation results are shown in Table 2. In this molded product, the high Tg component and the low Tg component were averaged, the glass transition temperature was lowered, and the heat resistance was lost.

(Comparative Example 3)
The same operation as in Production Example 3 was carried out except that the cobalt complex was not added in Production Example 1 and the amount of acrylic ester IBX added was 100 wt% to obtain polyisobornyl (meth) acrylate. The evaluation results are shown in Table 2. This molded product required a molding temperature of 250 ° C. or higher, which is the thermal decomposition temperature of polyisobornyl (meth) acrylate. Furthermore, because the resin was hard, it was not possible to obtain a complete molded piece as per the mold.

(Comparative Example 4)
The macromonomer (A) was prepared in the same manner as in Production Example 1 except that the monomer composition was changed, and the same as in Example 1 except that the addition amounts of the macromonomer (A), butyl acrylate, and methyl methacrylate were changed. The operation was performed. The evaluation results are shown in Table 3. In this molded product, the macromonomer (A), which is a heat-resistant component, does not have a glass transition temperature of 115 to 165 ° C., so that the Vicat softening temperature is 91.2 ° C., and the heat resistance is lowered.

(Comparative Example 5)
A macromonomer (A) was produced in the same manner as in Production Example 1. The same operation as in Example 1 was carried out with the addition amount of the macromonomer (A) being 45 wt% and the addition amount of butyl acrylate being 55 wt%. The evaluation results are shown in Table 3. In this molded product, the acrylic acid ester (B) exceeded the range of 10 to 50 wt%, and the phase separation structure of the macromonomer (A) and the acrylic acid ester (B), which are heat-resistant components, changed, so that the bicut softening temperature was increased. Decreased to 52.2 ° C.

(Comparative Example 6)
A macromonomer (A) was prepared in the same manner as in Production Example 1 except that the monomer composition was changed, and the same operation as in Example 1 was carried out. The evaluation results are shown in Table 3. In this molded product, the number average molecular weight (Mn) of the macromonomer (A) was out of the range of 1000 to 30000, and it is considered that the morphology of the macromonomer copolymer was changed. Since the polybutyl acrylate phase having a low Tg was compatible with the macromonomer (A) phase, the Vicat softening temperature was lowered to 39.2 ° C.

(Comparative Example 7)
A macromonomer (A) was produced in the same manner as in Production Example 1. The same operation as in Example 1 was carried out with the amount of the produced macromonomer (A) added being 98 wt% and the amount of butyl acrylate added being 2 wt%. The evaluation results are shown in Table 3. The viscosity of the reaction solution was very high and the polymerization did not proceed.

(Comparative Example 8)
A macromonomer (A) was produced in the same manner as in Production Example 1. The prepared macromonomer (A) was added in an amount of 55 wt%, butyl acrylate was added in an amount of 3 wt%, and methyl methacrylate was added in an amount of 47 wt%, and the same operation as in Example 1 was carried out. The evaluation results are shown in Table 3. In this molded product, the acrylic acid ester (B) was below the range of 10 to 50 wt%, and the resin fluidity was lowered. Therefore, 250 ° C., which is the thermal decomposition temperature of polyisobornyl (meth) acrylate, was required as the molding temperature.

(Comparative Example 9)
A macromonomer (A) was prepared in the same manner as in Production Example 1 except that the monomer composition was changed, and the same operation as in Example 1 was carried out. The evaluation results are shown in Table 3. In this molded product, the glass transition temperature of the macromonomer (A) exceeds the range of 115 ° C. to 165 ° C., the fluidity of the resin is low, and the molding temperature is 250 ° C., which is the thermal decomposition temperature of polyisobornyl methacrylate. It took as.

Claims (6)

The (meth) acrylic macromonomer (A) having a glass transition temperature of 115 ° C. to 165 ° C. is 50 to 90 wt%, and the glass transition temperature is 0 ° C. to -60 ° C. (meth) acrylic acid ester (B) 10 to 10. A method for producing a polymer that copolymerizes with 50 wt% .
The macromonomer (A) is a method for producing a polymer having a number average molecular weight (Mn) of 1000 to 30000 as measured by GPC using a calibration curve using polymethylmethacrylate as a standard substance. The method for producing a polymer according to claim 1, wherein the (meth) acrylic macromonomer (A) contains an isobornyl (meth) acrylate unit (a1) and a methyl methacrylate unit (a2) . At the time of the copolymerization, the (meth) acrylic acid ester (C) having a glass transition temperature of 100 ° C. or higher is further replaced with the macromonomer (A), the (meth) acrylic acid ester (B) and the (meth) acrylic acid ester. The method for producing a polymer according to claim 1 or 2 , wherein 0 to 45 wt% is copolymerized with respect to 100 wt% of the total of (C) . The method for producing a polymer according to any one of claims 1 to 3, wherein the copolymerization is a solution polymerization method. The method for producing a polymer according to claim 4, wherein the solvent used in the solution polymerization method is toluene or dimethylacetamide. A method for producing a resin molded product , comprising a step according to the method for producing a polymer according to any one of claims 1 to 5 and a step for molding the polymer according to the step .