JPS63273612A - Methacrylamide based copolymer - Google Patents

Abstract

PURPOSE:To obtain a copolymer which is a linear random copolymer, consisting of methacrylamide, styrene based structural and acrylonitrile units in a specific proportion, having a specific viscosity within a specified range and excellent heat and impact resistance, fluidity, etc. CONSTITUTION:A methacrylamide based copolymer which is a linear random copolymer, consisting of (A) 5-60mol.% methacrylamide units expressed by formula I, (B) 35-90mol.% styrene based structural units expressed by formula II (R<1>-R<3> are H, Cl, Br or 1-3C alkyl) and (C) 3-30mol.% acrylonitrile units expressed by formula III and having 0.1-0.5 specific viscosity (30 deg.C, 0.3g/100ml DMF). For example, the copolymer is prepared by reacting methacrylamide with styrene, acrylonitrile and, as necessary, <=20mol.% other copolymerizable monomers (e.g. maleic anhydride), normally at 30-250 deg.C for 0.5-16hr using an initiator, such as di-tert-butyl peroxide.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a methacrylamide copolymer having excellent heat resistance, fluidity, impact resistance, transparency and coloring resistance.

[Prior art and its problems] Polystyrene resin and acrylonitrile-styrene copolymer resin, which are known as general-purpose resins, have excellent moldability but low heat resistance.

Conventionally, as a method for improving the heat resistance of the above resins, monomers that increase heat resistance are copolymerized to produce styrene-maleic anhydride copolymers, styrene-methacrylic acid copolymers, and α-methylstyrene-acrylonitrile copolymers. There is a method to obtain copolymers with high heat resistance such as polymers. These methods have the effect of improving heat resistance to some extent, but on the other hand, the fluidity of the copolymer deteriorates due to the effects of hydrogen bonding of carboxyl groups in the molecule. There are many problems such as a decrease in processability, a decrease in transparency due to coloration due to thermal decomposition of acrylonitrile, and a decrease in impact resistance.

[Problems to be Solved by the Invention] The present invention aims to provide a methacrylamide-based copolymer which has improved heat resistance, fluidity, impact resistance, transparency, and coloring resistance and has improved the above-mentioned problems. purpose.

[Means for Solving the Problems] That is, the present invention provides methacrylamide units 5 to Bθ mol% represented by the formula % formula %, formula % formula % (wherein R1, R2 and R3 are a hydrogen atom and a chlorine atom, respectively) 35 to 90 mol% of styrenic structural units represented by atoms, bromine atoms, or alkyl groups having 1 to 3 carbon atoms
A linear random copolymer consisting of 3 to 30 mol% of acrylonitrile units represented by the formula % and N, N-
0.3g/10 of the copolymer in dimethylformamide
The present invention relates to a methacrylamide copolymer having a specific viscosity of 0.1 to 0.5 when measured using 0ml.

[Example] The specific viscosity of the copolymer of the present invention is 0.1-0.5. If the specific viscosity is less than 0.1, the molded product of the copolymer will be
, exceeds 0.5, the fluidity of the copolymer is significantly reduced. The specific viscosity of the copolymer of the present invention was measured using an Ostwald viscometer at 0.3 g/rooml in N,N-dimethylformamide solvent at 30°C.
The values measured using a solution of 0.3 g of the copolymer dissolved in 100 ml of N,N-dimethylformamide are shown.

The proportion of methacrylamide units represented by the formula % in the methacrylamide copolymer of the present invention is 5 to 60 mol%.

The proportion of methacrylamide units in the copolymer is 5 mol%
If it is less than 1, the effect of improving the heat resistance of the copolymer is small,
Moreover, if it exceeds 60 mol%, the fluidity of the copolymer becomes significantly low.

Particularly preferably, the proportion of methacrylamide units in the copolymer is preferably 10 to 45 mol %, since this provides a practical balance between heat resistance and fluidity.

Styrene represented by the formula % in the methacrylamide copolymer of the present invention (wherein R1, R2 and R3 each represent a hydrogen atom, a chlorine atom, a bromine atom or an alkyl group having 1 to 3 carbon atoms) The proportion of system structural units is 35-9
It is 0 mol%. The styrene structural unit has the effect of improving the fluidity of the copolymer, improves the transparency of the copolymer, and prevents coloring due to thermal decomposition of acrylonitrile. The proportion of styrene structural units in the copolymer is 35 mol%
If it is less than 1, the fluidity of the copolymer is extremely low
If it exceeds 90 mol%, impact resistance is low. In addition, examples of the styrene structural unit in the present invention include styrene, orthochlorostyrene, parachlorostyrene, orthobromostyrene, varabromostyrene, orthomethylstyrene, paramethylstyrene, orthoethylstyrene, paraethylstyrene, orthoisopropyl. Styrene, diisopropylstyrene, 2,4-dichloro6-styrene, 2,8-dichlorostyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-chloro-
Structural units such as 2-methylstyrene and 2.4.8-)dimethylstyrene are mentioned, and among these, the styrene unit is particularly preferred since it is advantageous in terms of monomer availability and cost.

Further, the proportion of acrylonitrile units expressed by the formula % in the copolymer of the present invention is 3 to 30 mol%. By using acrylonitrile as a structural unit of the copolymer of the present invention, impact resistance can be improved. The proportion of acrylonitrile units in the copolymer is 3
If it is less than mol%, there will be little effect of improving the impact resistance of the copolymer, and if it exceeds 30 mol%, the copolymer may become colored due to thermal decomposition of acrylonitrile, or the copolymer may become discolored. This is not preferable because it causes a problem that the fluidity of the polymer decreases.

Particularly preferably, the proportion of acrylonitrile units in the copolymer is 5 to 20 mol %, since this provides a practical balance between impact resistance and fluidity.

Examples of monomers constituting the methacrylamide copolymer of the present invention include methacrylamide, styrene monomers forming styrene structural units, and acrylonitrile, as well as monomers copolymerizable therewith, such as maleic anhydride, N- Monomers such as phenylmaleimide, α-methylstyrene, methacrylate tol, and methyl methacrylate are used alone or in combination of two or more in the copolymer of the present invention in an amount of 0 to 20 mol%.
It can be used so that the copolymerization ratio is as follows.

If the above monomer is used as a constituent monomer of the copolymer,
Properties such as improved heat resistance can be imparted to the copolymer. However, if the copolymerization ratio of the monomer in the copolymer exceeds 20 mol %, the fluidity of the copolymer tends to decrease significantly.

The method of copolymerization in the present invention is not particularly limited, and includes ordinary suspension polymerization, emulsion polymerization, bulk polymerization,
A solution polymerization method etc. can be used.

During the reaction, benzoyl peroxide,
Peroxides such as butyl peroxide, azo compounds such as 2.2°-azobisisobutyronitrile, l,1°-azobis(l-cyclohexanecarbonitrile), potassium persulfate, ammonium persulfate, etc. Known initiators such as persulfates are preferably used. It is practical to add 0.001 to 3 parts by weight of these initiators to 100 parts by weight of the total monomers constituting the copolymer of the present invention for balancing the conversion rate and polymerization time and adjusting the molecular weight. It is preferable because it is. Also, known organic dispersants such as methylcellulose and polyvinyl alcohol, inorganic dispersants such as tricalcium phosphate and magnesium phosphate, emulsifiers such as sodium valmitate, and surfactants such as sodium dodecylbenzenesulfonate can be used. Dispersants, emulsifiers, and surfactants are optional for uniformly dispersing the monomers and copolymers in a medium such as water, and the sum of the monomers constituting the copolymer of the present invention. 0.0 per 100 parts by weight
It is preferable to add 1 to 3 parts by weight. The reaction is usually 30
It is carried out for 0.5 to 16 hours at ~250°C.

In order to adjust the specific viscosity to the above-mentioned specific viscosity, known chain transfer agents such as rt-dodecylmercaptan and 2-mercaptoethanol, and known polyfunctional compounds such as diallyl phthalate, diethylene glycol diacrylate, and diethylene glycol dimethacrylate are used during production of the copolymer. It is preferable to add 0.001 to 1 part by weight to a total of 100 parts by weight of the monomers constituting the copolymer of the present invention, as necessary, for the reason that the specific viscosity can be easily adjusted. preferable.

In addition, known lubricants such as behenic acid, stearic acid, and liquid paraffin may be added to the methacrylamide copolymer of the present invention during the production of the copolymer (monomers constituting the copolymer of the present invention). 0.1 to 100 parts of total body weight
It is preferable to add 5 parts by weight because it improves the fluidity of the copolymer.

The copolymer obtained in the present invention may be used alone, and may be used as the above-mentioned lubricant or the known 2,6-di-1(3rt-butyl-4-
It may be used in blends with stabilizers such as methylphenol, colorants such as titanium oxide and red iron oxide, flame retardants such as hexabromobenzene, and various other polymers. It is preferable to add o, oi to 5 parts by weight to a total of 100 parts of TIl because it does not cause deterioration in processability and physical properties. Various polymers to be blended include polycarbonates such as polymers produced by the reaction of bisphenol A and phosgene;
Polyarylates such as polycondensation polymers consisting of bisphenol A and phthalic acid; engineering plastics such as polyamide resins such as nylon 6 and nylon 68; polyamides such as vinyl chloride homopolymers and vinyl chloride-vinyl acetate copolymers. Vinyl chloride resin; chlorine content 58
Chlorinated vinyl chloride resin with a content of 70% by weight or more, MBS resin such as a graft copolymer obtained by grafting 20 to 80% by weight of styrene and methyl methacrylate onto a diene rubber containing 50% by weight or more of butadiene, and a chlorine content of 20 to 80% by weight. 50
Chlorinated polyethylene resin such as chlorinated polyethylene in weight%; acrylic rubber resin such as rubber mainly composed of ethyl acrylate and butyl acrylate; random copolymer containing ff120 to 50% by weight of acrylonitrile and butadiene as the main component There are known resins such as NBR resins such as .

The copolymer of the present invention can be processed and molded using an injection molding machine, a roll molding machine, or an extrusion molding machine, and is used in the form of a plastic molded body, a foamed body, or the like.

Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples.

Example 1 A monomer and di-tert-butyl peroxide as an initiator were charged into an autoclave having an internal volume of 31 cm and equipped with a stirrer, adjusted to have the charging ratio shown in Table 1, and the autoclave was purged with nitrogen. The temperature inside the autoclave was raised to 130°C, and polymerization was carried out for 2 hours. Thereafter, the copolymer was heated to 200° C. and residual unreacted monomers were removed under reduced pressure of 5 + u + Hg, and then the copolymer was taken out from the bottom of the autoclave.

The obtained copolymer was colorless and transparent.

Equipment (Heraeus, CllN-0-
Measure the proportions of methacrylamide units, styrenic structural units, and acrylonitrile units in the obtained copolymer by elemental analysis using a 3D (Rapid) method, that is, the copolymerization ratio of each monomer in the obtained copolymer. did. The results are shown in Table 1.

Further, the specific viscosity of the obtained copolymer was measured using an Ostwald viscometer at 0.3 g/loOml in an N,N-dimethylformamide solvent at 30°C.

The results are shown in Table 1.

Further, the obtained copolymer was molded into test pieces having dimensions corresponding to each measurement using an injection molding machine with a mold clamping cuff of 5 tons (manufactured by Messai Resin Kogyo ■, FS-150).

The physical properties of the copolymer obtained using the test piece were evaluated for heat resistance, fluidity, impact resistance, transparency, and coloring resistance according to the following methods. The results are shown in Table 1.

(Heat resistance) According to the test method specified in JIS K 720B, a load of 5
kg/c- condition, 2hm x 2hm x 3
am test piece and Vicat softening temperature tester (
The Vicat softening temperature was measured using a YSS tester (manufactured by Yasuda Seisakusho) and used as a criterion for determining heat resistance.

If the Vicat softening temperature is 105°C or higher, it is practical.

(Fluidity) According to the test method specified in JIS K 7210, a load of 1
A sample extruded in 1 second by method B flow using a pellet-shaped test piece and an extrusion type blast meter (Flow Tester, NT-3, manufactured by Shimadzu Corporation) under the conditions of 00 kg/c and a measurement temperature of 240 °C. 0. If the fluidity is 10' cc/sec or more, the processability is good.

(Impact resistance) According to the test method specified in JIS K 7110, without notches, at a temperature of 23°C and a relative humidity of 50%,
．． 7mm x 885mm x 12.7aus test piece and Izotsu impact tester (manufactured by Toyo Seiki)
The Izot impact value was measured using the Izot impact value and used as a criterion for impact resistance.

The larger the Izot impact value is, the more practical it is.

(Transparency) According to the test method specified in JIS K 6714, 50 m
Parallel light transmittance was measured using a test piece of mX50+nmX3 mm and an integrating sphere type light transmittance measuring device, and transparency was evaluated according to the following criteria.

(Judgment criteria) ◎ - Parallel light transmittance is 85% or more ○: Parallel light transmittance is 80% or more and less than 85% Δ: Parallel light transmittance is 70% or more and less than 80% ×: Parallel light transmittance is less than 70% ◎ and ○ are usable as molded products, but Δ and × are not practical in terms of transparency.

(Coloring Resistance) The test pieces were visually inspected and the transparency was evaluated according to the following criteria.

(Judgment criteria) ○: Almost no coloring.

Δ: Very light yellow coloring.

×: Yellow coloring present.

In terms of appearance, those marked O and Δ can be practically used.

Examples 2 and 3 and Comparative Examples 1 and 2 Example 1 except that the amount of the initiator di-tert-butyl peroxide was adjusted as shown in Table 1.
A copolymer was obtained according to the same method. The copolymerization ratio of monomers in the obtained copolymer was measured in the same manner as in Example 1. The results are shown in Table 1. Also,
The specific viscosity and physical properties of the resulting copolymer include heat resistance,
Fluidity, impact resistance, transparency and coloring resistance were determined in the same manner as in Example 1. The results are shown in Table 1.

Examples 4 to 9 and Comparative Examples 3 to 8 In Example 1, the monomer charging ratio was adjusted as shown in Table 1, and the blending amount of the initiator di-tert-butyl peroxide was 0.10% by weight. A copolymer was obtained in the same manner as in Example 1 except that The copolymerization ratio of monomers in the obtained copolymer was measured in the same manner as in Example 1. The results are shown in Table 1. Further, the specific viscosity and physical properties of the obtained copolymer, such as heat resistance, fluidity, impact resistance, transparency, and coloring resistance, were determined in the same manner as in Example 1. The results are shown in Table 1.

Examples 1O to 16 In Example 1, the styrenic monomer shown in Table 2 was used instead of styrene, and the initiator tθrt
A copolymer was obtained in the same manner as in Example 1, except that the amount of -butyl peroxide was changed to the amount shown in Table 2. The copolymerization ratio of monomers in the obtained copolymer was measured in the same manner as in Example 1. The results are shown in Table 2. Further, the specific viscosity and physical properties of the obtained copolymer, such as heat resistance, fluidity, impact resistance, transparency, and coloring resistance, were determined in the same manner as in Example 1.

The results are shown in Table 2.

[Left below] As can be seen from Table 1, in Comparative Example 1, the specific viscosity was 0.07, which is less than 0.1, so the impact resistance of the copolymer molded product was lower than that of Examples 1 to 3. It was extremely low. In Comparative Example 2, the specific viscosity exceeded 0.5 and was 0.
．． 55, the fluidity was significantly lower than in Examples 1 to 3. In Comparative Example 3, the copolymerization ratio of methacrylamide in the copolymer, that is, the proportion of methacrylamide units in the copolymer, was 2.5, which was less than 5 mol%.
Because it is mol%, the heat resistance of the copolymer is as low as 97°C.
In addition, in Comparative Example 4, the copolymerization ratio of methacrylamide in the copolymer exceeded 80 mol% and was 63.8 mol%, so the copolymer was decomposed during molding, making it impossible to prepare a test piece. could not. Furthermore, in Comparative Example 5, the copolymerization ratio of acrylonitrile in the copolymer was 30
Since the amount exceeded 40.2 mol %, the copolymer molded product was colored yellow, and the fluidity was significantly lower than in Example 4. In Comparative Example 6, in which only styrene and methacrylic acid were used without using methacrylamide and acrylonitrile, the fluidity and impact resistance of the copolymer were lower than in Example 2.

[Effects of the Invention] The methacrylamide copolymer of the present invention has excellent heat resistance, fluidity, impact resistance, transparency, and coloring resistance, so it can be used in various injection molded products, extrusion foam molded products, etc. It has a soothing effect.

Claims (1)

[Claims] 1 5 to 60 mol% of methacrylamide units represented by the formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ^2 and R^3 each represent a hydrogen atom, a chlorine atom, a bromine atom, or an alkyl group having 1 to 3 carbon atoms) Styrenic structural unit 35 to 90
A linear random copolymer consisting of 3 to 30 mol% of acrylonitrile units represented by mol% and formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼
0.3g/10 of the copolymer in dimethylformamide
A methacrylamide copolymer having a specific viscosity of 0.1 to 0.5 when measured using 0 ml. 2 The proportion of methacrylamide units in the copolymer is 10 to
The methacrylamide copolymer according to claim 1, which has a content of 45 mol%. 3 The proportion of acrylonitrile units in the copolymer is 5 to 2
The methacrylamide copolymer according to claim 1 or 2, which has a content of 0 mol %. 4. The methacrylamide copolymer according to claim 1, 2 or 3, wherein the styrene structural unit is a styrene unit.