JPH06234822A - Method for producing graft copolymer - Google Patents

Abstract

PURPOSE:To obtain a method for producing an acrylic or a methacrylic graft copolymer excellent in weather resistance, transparency, etc. CONSTITUTION:This method for producing a graft copolymer is to copolyjnerize a methacrylic acid ester-based macromonomer having 3000-100000 number- average molecular weight, >=40 deg.C glass transition temperature and (meth)acryloyl group at one terminal with an acrylic or a methacrylic acid ester capable of providing homopolymer thereof having <=0 deg.C glass transition temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a (meth) acrylic graft copolymer having excellent weather resistance and transparency.

[0002]

2. Description of the Related Art Block copolymers and graft copolymers have been developed for the purpose of enhancing the functionality and performance of polymer materials. Recently, due to progress in the synthesis technology of oligomers and polymers (macromonomers) having a polymerizable functional group at one terminal, interest has been focused on the development and application of graft copolymers using these. Various methods have been proposed to date as methods for synthesizing macromonomers and methods for producing graft copolymers. For example, a method for producing a graft copolymer using a macromonomer synthesized by an anionic polymerization method such as Milkovich (JP-A-47-21486).
JP-A-50-116586, etc.), a method for producing a graft copolymer using a macromonomer synthesized by a radical polymerization method of ICI or Du Pont (Japanese Patent Publication No. 43-11224).
JP-B-43-16147, USP 3689593, etc.), a method for producing a macromonomer having a vinylphenyl group at one end by the group transfer polymerization method of Toa Gosei Chemical Industry Co., Ltd. (JP-A-62-62801), etc. There is.

[0003]

However, in the above-mentioned and the above methods, since the composition of the graft copolymer is distributed depending on the copolymerization reactivity ratio of the polymerizable vinyl group of the macromonomer and the comonomer, the composition distribution control is performed. As a countermeasure, it is necessary to control the addition rate of the macromonomer and the comonomer, and the resulting copolymer also has insufficient weather resistance and transparency. Further, according to the above method, it is difficult to obtain a graft copolymer having a structure regulated according to the molecular design and excellent in melt fluidity, weather resistance, transparency and mechanical properties in a high yield.

The object of the present invention is that the composition ratio of the components of the (meth) acrylic acid ester that constitutes the trunk and branches of the graft copolymer can be selected in a wide range, and the chain length of the trunk and the branch portion can be selected. It is an object of the present invention to provide a method for producing a (meth) acrylic graft copolymer having a controlled chain length and excellent weather resistance, transparency and mechanical properties in a high yield.

[0005]

Means for Solving the Problems The gist of the present invention is to provide a methacrylic acid ester-based macromonomer having a (meth) acryloyl group at one end and having a number average molecular weight of 3,000 to 100,000 and a glass transition temperature of 40 ° C. or higher. , A homopolymer having a glass transition temperature of 0 ° C. or lower and a (meth) acrylate ester.

The methacrylic acid ester type macromonomer having a (meth) acryloyl group at one end used in the present invention is a component which becomes a branch portion of the graft copolymer by copolymerization.

The main chain of the methacrylic acid ester-based macromonomer is composed of one or more kinds of methacrylic acid ester units such as methyl methacrylate (MMA), and methacrylic acid, A small amount of vinyl monomer units such as acrylic acid ester and acrylonitrile may be contained. The (meth) acryloyl group at one end of the macromonomer is preferably an acryloyl group.

The number average molecular weight of this macromonomer measured by the GPC method is in the range of 3,000 to 100,000. If the molecular weight is less than this range, it is difficult to obtain a graft copolymer having sufficient properties, and if the molecular weight exceeds this range, the reactivity decreases. Molecular weight is 5000
It is preferably in the range of up to 50,000. The glass transition temperature of this macromonomer is 40 ° C. or higher, but 60 ° C. or higher is more preferable.

Such macromonomers are, for example, M
A method of anionically polymerizing MA or the like and then reacting it with a halogen-containing (meth) acryloyl compound, a method of radically polymerizing MMA or the like in the presence of mercaptoacetic acid and then reacting it with a glycidyl group-containing (meth) acrylic ester, trimethylsiloxy It can be obtained by group transfer polymerization of MMA or the like using ethyltrimethylsilyldimethylketene acetal as an initiator, and then reacting with (meth) acryloyl chloride. Those produced by the group transfer polymerization method in consideration of the copolymerization characteristics and the melt moldability of the resulting copolymer are most preferable.

In the present invention, as the (meth) acrylic acid ester copolymerized with the macromonomer, the poly (meth) acrylic acid ester obtained by polymerizing only the monomer component has a glass transition temperature of 0 ° C. or lower. Is used.

As a specific example, ethyl acrylate (E
A), butyl acrylate (BA), lauryl methacrylate (LMA) and the like. These can be used as a mixture of two or more, but ethyl acrylate (E
A) and butyl acrylate (BA) are preferred.

The (meth) acrylic acid ester is copolymerized with the macromonomer to form the trunk of the graft copolymer.

The composition ratio of the macromonomer and the (meth) acrylic acid ester in the copolymerization reaction is not particularly limited, but the composition of both components in the resulting graft copolymer is about 20-80 / 80-20% by weight. Is preferred.

In the present invention, the polymerization method of the graft copolymer is mainly a solution polymerization method or a solution suspension polymerization method, but a polymerization reaction method without using a solvent is also possible.

In the case of the solution polymerization method, a chlorinated hydrocarbon solvent, tetrahydrofuran (THF), acetone, methyl ethyl ketone (MEK), benzene, toluene, xylene and the like are used as the solvent.

[0016]

EXAMPLES Hereinafter, the present invention will be described more specifically by way of examples. In the examples, various physical properties were evaluated by the following methods. Tensile modulus, tensile breaking strength, breaking elongation
-Compliant with 638. The light transmittance was based on ASTM D-1003. However, the thickness of the resin was 3.2 mm. Weather resistance is
Evaluation was made by the elongation retention rate and yellowness change (ΔYI) after exposure for 3000 hours to a sunshine weather meter.

Reference Example 1 Synthesis of MMA macromonomer having an acryloyl group at one end: 2.8 g (10.0 mmol) of trimethylsiloxyethyl trimethylsilyldimethylketene acetal and trisdimethylaminosulfur trimethylsilylbifluor in 400 ml of anhydrous THF under dry argon. Ride (TAS ⁺ (CH ₃ ) ₃ S
iF ₂ ^-) 0.03 g of (0.11 mmol) was added, then dried MMA200
g (2.0 mol) was added dropwise, and the mixture was polymerized at 0 ° C. for 3 hours. Next, this polymer was added to 6 liters of a hydrochloric acid-containing methanol solution,
The precipitate was washed with methanol and vacuum dried at 150 ° C. for 12 hours. As a result, 180 g of poly (MMA) having a hydroxyl group at one end with Mn = 21000 and Mw / Mn = 1.10 was obtained (yield 90%).
.

Further, 90 g of this poly MMA (amount of hydroxyl group 4.3 mm
ol) was dissolved in 450 ml of anhydrous THF and triethylamine was added.
1.01 g (10.0 mmol), acryloyl chloride 0.91 g (10.0 mmol)
Was added and reacted at room temperature for 24 hours. This reaction product was treated with methanol.
Add to 10 liters, wash precipitate with methanol and
h Vacuum dried. As a result, 81 g of MMA macromonomer having an acryloyl group at one end was obtained (yield 90
%). The introduction rate of the acryloyl group at the terminal was 96% as measured by NMR. The glass transition temperature measured by differential scanning calorimetry (DSC) was 102 ° C.

Reference Example 2 Synthesis of MMA macromonomer having methacryloyl group at one end Poly polyMM having a hydroxyl group at one end synthesized in Reference Example 1
A (90 g of hydroxyl group: 4.3 mmol) was dissolved in 450 ml of anhydrous THF, 1.01 g (10.0 mmol) of triethylamine and 1.05 g (10.0 mmol) of methacryloyl chloride were added, and the mixture was reacted at room temperature for 24 hours. The reaction product was added to 10 liters of methanol, and the precipitate was washed with methanol and dried under vacuum at 50 ° C. for 12 hours. As a result, 80 g of MMA macromonomer having a methacryloyl group at one end was obtained (yield 90%). The introduction rate of methacryloyl groups to the terminal was 86%. The glass transition temperature was 102 ° C.

Example 1 Synthesis of EA / MMA Graft Copolymer 40 g of MMA macromonomer having an acryloyl group at one end synthesized in Reference Example 1, 60 g of EA and 0.5 g of benzoyl peroxide (BPO) were collectively added to 300 ml of toluene. Dissolve
After sufficiently substituting with nitrogen, the mixture was reacted at 80 ° C for 3 hours. The reaction product was reprecipitated with hexane and then vacuum dried to obtain EA / MM.
84 g of A graft copolymer (EA / MMA = 60/40) was obtained (yield 84%). The yield, total light transmittance, tensile strength and elongation and weather resistance of the obtained graft copolymer are shown in Table 1.

Example 2 Synthesis of EA / MMA Graft Copolymer MMA macromonomer having an acryloyl group at one end, synthesized in the same manner as in Reference Example 1, 60 g, EA 40 g, B
0.5 g of PO was dissolved in 300 ml of toluene all at once, and the atmosphere was sufficiently replaced with nitrogen, followed by reaction at 80 ° C. for 3 hours. The reaction product was reprecipitated with hexane and then vacuum dried to obtain 90 g of an EA / MMA graft copolymer (EA / MMA = 40/60) (yield 9
0%). The yield, total light transmittance, tensile strength and elongation and weather resistance of the obtained graft copolymer are shown in Table 1.

Example 3 Synthesis of BA / MMA Graft Copolymer MMA macromonomer having an acryloyl group at one end synthesized in the same manner as in Reference Example 40, BA 60 g, B
0.5 g of PO was dissolved in 300 ml of toluene all at once, and the atmosphere was sufficiently replaced with nitrogen, followed by reaction at 80 ° C. for 3 hours. The reaction product was reprecipitated with methanol and then vacuum dried to obtain 86 g of BA / MMA graft copolymer (BA / MMA = 60/40) (yield 8
6%). The yield, total light transmittance, tensile strength and elongation and weather resistance of the obtained graft copolymer are shown in Table 1.

Example 4 Synthesis of LMA / MMA Graft Copolymer MMA macromonomer 40 g, LMA 60 g, BPO synthesized in Reference Example 2 and having methacryloyl group at one end
0.5 g was dissolved all at once in 300 ml of toluene, the atmosphere was sufficiently replaced with nitrogen, and the mixture was reacted at 80 ° C. for 3 hours. The reaction product was reprecipitated with methanol and then vacuum dried to obtain 85 g of LMA / MMA graft copolymer (LMA / MMA = 60/40) (yield 8
Five%). The yield, total light transmittance, tensile strength and elongation and weather resistance of the obtained graft copolymer are shown in Table 1.

Comparative Example 1 M having a styryl group at one end
Synthesis of MA macromonomer Vinyl phenyl ketene methyl trimethyl silyl acetal (VPKT) in 200 ml of anhydrous THF under dry argon.
SA) 1.2 g (5.0 mmol) and trisdimethylaminosulfur trimethylsilyl bifluoride (TAS ⁺ (CH ₃ ) ₃ S
iF ₂ ^-) 0.03g (0.11mmol) and dry MMA 100g (1.0mol)
Was added and polymerized at 0 ° C. for 3 hours. It was added to a hexane solution containing 5% methanol, and the precipitate was vacuum dried at 50 ° C for 12 hours.
90 g of MMA macromonomer having a styryl group at one end of n = 22000 and Mw / Mn = 1.20 was obtained (yield 90%). The introduction rate of the styryl group was 100%.

This MMA macromonomer-40g, BA60g
, BPO (0.5 g) were collectively dissolved in 300 ml of toluene, and the atmosphere was sufficiently replaced with nitrogen, and then the mixture was reacted at 80 ° C for 3 hours. The reaction product was reprecipitated with methanol and then vacuum dried to obtain BA / MMA.
80 g of a graft copolymer (BA / MMA = 60/40) was obtained (yield 80%). The yield, total light transmittance, tensile strength and elongation, and weather resistance of the obtained graft copolymer are shown in Table 1.

[0026]

[Table 1]

[0027]

According to the method for producing a graft copolymer of the present invention, the components of the (meth) acrylic acid ester forming the trunk of the graft copolymer and the component of the (meth) acrylic acid ester forming the branch are broad. It is possible to produce a high yield of a (meth) acrylic graft copolymer which can be selected in the range and whose chain length and branch chain length are both controlled.
Further, according to the production method of the present invention, it is possible to obtain a (meth) acrylic resin and an elastomer having excellent transparency, weather resistance and mechanical properties.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Nakata 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Central Research Laboratory (72) Naoki Yamamoto 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Central Research Laboratory

Claims (1)

[Claims] 1. A methacrylic acid ester-based macromonomer having a (meth) acryloyl group at one end thereof having a number average molecular weight of 3,000 to 100,000 and a glass transition temperature of 40 ° C. or higher, and a glass transition temperature of a homopolymer thereof. A method for producing a graft copolymer, which comprises copolymerizing a (meth) acrylic acid ester having a temperature of 0 ° C or lower.