JPS6239611A - Production of thermoplastic resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin having improved heat resistance, impact strength and modability, by graft copolymerizing a graft polymerizable elastomer with a monomer mixture by a method for adding the above-mentioned elastomer to the reaction system in divided portions before and after the phase inversion and imidating the resultant polymer. CONSTITUTION:(A) 10-90wt%, based on the total amount to be used in a reaction, graft polymerizable elastomer is first added to the reaction system, and the remainder is added thereto after the phase inversion. Thereby, 60-95pts. wt. mixture consisting of (B) 50-90wt% aromatic vinyl monomer, preferably styrene, (C) 5-40wt% unsaturated dicarboxylic acid anhydride, preferably maleic anhydride and (D) 0-30wt% vinyl monomer copolymerizable therewith, preferably acrylic acid is graft polymerized with 5-40pts.wt. component (A). The resultant polymer is then imidated with ammonia and/or a tertiary amine, preferably aniline to afford the aimed resin.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a method for combining an aromatic vinyl monomer grafted onto an elastomer and an acid anhydride residue in a copolymer mainly composed of an unsaturated dicarboxylic acid. Regarding the method for producing a thermoplastic resin made of an imidized copolymer, the thermoplastic resin composition containing the thermoplastic resin obtained by the present invention has excellent heat resistance, impact strength, and moldability, It can be preferably used for automobile parts, electrical and electronic parts, office equipment parts, household electrical parts, medical equipment parts, camera parts, etc.

(Prior art) A method for producing a copolymer consisting of an aromatic vinyl monomer, maleic anhydride and other vinyl monomers (Japanese Patent Publication No. 40
-15829, Special Publication No. 45-31953, Special Publication No. 4
No. 9'-10156) is known. We also proposed a method for producing a thermoplastic copolymer with improved impact resistance by graft polymerizing maleic anhydride, an aromatic vinyl monomer, and/or a vinyl monomer copolymerizable with these onto a graft-polymerizable elastomer. (Japanese Patent Application Laid-Open No. 48-42091
No., JP-A-49-28693, JP-A-53-7825
No. 2, Japanese Unexamined Patent Publication No. 5:3-80490).

However, these copolymerized maleic anhydride polymers are
Although it has a high heat distortion temperature, in both cases the copolymer has the disadvantage of being easily decomposed by hot water and easily gelling and foaming due to heat, so there are significant restrictions when injection or extrusion processing is performed. However, when a processed product is brought into contact with water vapor or exposed to high temperatures, the mechanical properties, particularly the impact strength, deteriorate.

In order to improve these drawbacks, methods and compositions for producing copolymers in which maleic anhydride is replaced with maleimide derivatives have also been proposed (U.S. Pat. No. 3,651,171, U.S. Pat. No. 3,652,726, JP-A-57-98536). issue)
.

(Problems to be Solved by the Invention) However, although these copolymers or compositions have improved heat stability and hot water resistance, they still have the drawback of being insufficient in impact strength and moldability.

(Means for Solving the Problems) The present invention solves these drawbacks, and by adding the graft polymerizable elastomer used in kraft polymerization separately before and after phase inversion, it improves not only heat resistance but also impact strength. The present invention aims to provide a thermoplastic resin that also has excellent moldability. Aromatic vinyl monomer 50~ in the old building
90% by weight, unsaturated dicarboxylic anhydride 5-40%
, and 60 to 95 parts by weight of a monomer mixture consisting of 0 to 30% by weight of a vinyl monomer copolymerizable with these, and then imidized with ammonia and/or a primary amine to form a thermoplastic material. (In a method for producing sealants, 10 to 90% by weight of the total amount of elastomer used in graft polymerization is added before phase inversion, and the remaining 90 to 1% by weight is added to the total amount of elastomer used in graft polymerization.
This is a method for producing a thermoplastic resin, characterized in that 0% by weight of an elastomer is added after rolling to carry out graft polymerization.

According to the method of the present invention, a grafted body can be obtained in which the grafting efficiency of the elastomer is lower than that of the conventional method. In short, it is presumed that thermoplastic resins with poor heat resistance, impact strength, and moldability can be obtained by using elastomers with different graft efficiencies.

The graft-polymerizable elastomers used in the present invention include a buxene polymer, a copolymer of butadiene and a copolymerizable vinyl monomer, an ethylene-propylene co-F4i polymer, an ethylene-propylene-diene copolymer, and a butadiene and aromatic copolymer. Block copolymers with group vinyl, acrylic ester polymers, and copolymers of acrylic esters with vinyl monomers copolymerizable therewith are used.

Examples of aromatic vinyl monomers include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, and chlorostyrene, substituted monomers thereof, and mixtures thereof; among these, styrene is Particularly preferred. The unsaturated acid anhydride includes anhydrides such as maleic acid, itaconic acid, citraconic acid, aconi-nodic acid, and mixtures thereof, with maleic anhydride being particularly preferred. Vinyl monomers that can be copolymerized with these include acrylonitrile and methacrylonitrile.

Vinyl cyanide monomers such as α-chloroacrylonitrile, single acrylic esters such as methyl acrylate, ethyl acrylate, and butyl acrylate, methacrylic esters such as methyl methacrylate and ethyl methacrylate monomers, vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid, acrylic acid amide, methacrylic acid amide, acenaphthylene and N-vinylcarbazole, and mixtures thereof, among which acrylonitrinobemethacrylic acid Monomers such as esters, acrylic acid, methacrylic acid are preferred.

In the present invention, the content of the graft polymerizable elastomer can be selected in the range of 5 to 40% by weight based on the copolymer before imidization, depending on the impact strength required of the thermoplastic resin. As the content of the graft polymerizable elastomer increases, the impact strength improves, but if the content of the graft polymerizable elastomer exceeds 40% by weight, the heat resistance and molding processability of the final thermoplastic resin are poor, and 5
If it is less than % by weight, the impact improving effect is insufficient.

In the present invention, the monomers to be grafted to the graft polymerizable elastomer include 50 to 90% by weight of aromatic vinyl monomers;
It is a mixture consisting of 5 to 50% by weight of an unsaturated dicarboxylic acid anhydride and 0 to 30% by weight of a vinyl monomer copolymerizable with these, and if the aromatic vinyl monomer is less than 50% by weight, it is an aromatic vinyl. Characteristics of compounds, especially in the case of styrene,
Formability and dimensional stability are lost. Furthermore, if the content of unsaturated dicarboxylic acid anhydride is less than 5% by weight, heat resistance is insufficient;
If it exceeds 50% by weight, the copolymer becomes brittle and its moldability deteriorates significantly.

When copolymerizing an aromatic vinyl monomer and an unsaturated dicarboxylic anhydride, since both have strong alternating copolymerizability, the consumption rate of the latter is fast, so a small amount of the unsaturated dicarboxylic anhydride is added to the polymerization system. It is also possible to adopt a method in which the copolymerization composition is made uniform by adding the components one by one. In addition, in order to intentionally make the copolymerization composition non-uniform and obtain a sequence of unsaturated dicarboxylic anhydrides, we also adopted a method in which unsaturated dicarboxylic anhydrides are added to the polymerization system intermittently during the polymerization period. It is possible. However, the method of adding all of the unsaturated dicarboxylic anhydride used at the beginning of the reaction is such that the composition of the unsaturated dicarboxylic acid anhydride is 20%.
It can be used if it is low (weight M% or less), but if the composition contains more unsaturated dicarboxylic anhydride, the reaction will run out of control in the early stage of polymerization, resulting in alternating copolymerization with a high content of insoluble unsaturated dicarboxylic acid from the polymerization system. Since substances having a composition similar to that of coalescence precipitate, in order to avoid this it is necessary to use a reaction mixture with extremely high heat removal ability or to use a large amount of solvent, which is economically disadvantageous.

The unsaturated dicarboxylic anhydride can be added to the polymerization system by preparing and adding a solution of the unsaturated dicarboxylic anhydride in an aromatic vinyl monomer solution or its solvent; Any method can be adopted, such as a method of melting and adding.

In the present invention, as a specific method for adding the elastomer, for example, in a batch polymerization method, 10 to 90% by weight of the elastomer to be used is added at the initial stage of the reaction before phase inversion, and the polymerization reaction is continued. After the process has proceeded and phase inversion of the elastomer has occurred, the remainder of the elastomer, i.e. 90-10% by weight, is added to the polymerization system.

Phase inversion here means that polymerization progresses from a state in which the diistomer forms a continuous phase and the monomer and polymer solution form a dispersed phase, and the monomer and polymer solution form a continuous phase and the elastomer forms a dispersed phase. The phase inversion phenomenon refers to the phenomenon in which a transparent elastomer solution becomes cloudy and the rapid change in the viscosity of the system that increases with the progress of polymerization, i.e., the appearance of maximum and minimum values in the viscosity of the system. Here, "before phase inversion" refers to the time before the viscosity of the system reaches its maximum value, and "after phase inversion" refers to the time after the viscosity of the system reaches its minimum value.After the phase inversion, the elastomer dispersed phase becomes a so-called "helical structure" containing a polymer phase. Adding the elastomer after the phase inversion, that is, while the viscosity of the system is rapidly decreasing, is not preferred because the system becomes unstable. This addition method includes a method in which the elastomer is added continuously immediately after the phase inversion, a method in which the elastomer is added in several parts at time intervals, a method in which the remaining elastomer is added at a certain period after the phase inversion, etc. be able to.

For example, in a continuous polymerization method, 10 to 90% by weight of the elastomer to be used is added continuously to the first (soda) and turned over, and the remainder of the elastomer, i.e. 90% by weight, is Continuously add up to 10 layers of 96. This addition method can be used to continuously add to multiple tanks after the second tank or only to one or more selected tanks after the second tank. Addition methods, methods of continuous addition at one point or multiple points in a continuous horizontal reaction tank exhibiting piston flow, and other methods are adopted.The temperature for the polymerization reaction is suitably in the range of 50°C to 180°C; If the polymerization temperature is too low, the reaction takes too long, and if it is higher than that, the polymerization rate is too fast and a runaway reaction is likely to occur, which is dangerous.

At high polymerization temperatures of 100°C or higher, so-called thermal graft polymerization can be carried out without a catalyst by thermal radical initiation of styrene; Of course, it is also possible to carry out conventional radical graft polymerization using a radical initiator such as butyronitrile.

The polymerization process may be a batch process using a vertical polymerization tank or the like in one or more stages, a -1 stage process, or a continuous process in which vertical or horizontal polymerization apparatuses are connected in one or more stages. If necessary, additives such as antioxidants, ultraviolet absorbers, lubricants, plasticizers, and colorants can be added as appropriate before, during, or after polymerization.

Ammonia and primary amines used in the imidization reaction of the present invention may be in either an anhydrous or aqueous state, and examples of primary amines include methylamine, ethylamine, n-propylamine, isopropylamine, and butylamine. , pentylamine, cyclohexylamine, and their chlor- or bromo-substituted alkyl amines; aromatic amines such as aniline, tolylamine, naphthylamine; and halogen-substituted aromatic amines such as chloro- or bromo-substituted aniline; and mixtures thereof. Among these, aniline is particularly preferred.

In the present invention, when the rubbery polymer-aromatic vinyl-unsaturated dicarboxylic acid anhydride copolymer is imidized with ammonia and/or primary amine, a corner solvent may be present, and usually a tertiary solvent may be present. grade amines are used.

When the imidization reaction is carried out in a solution or suspension state, it is preferable to use a conventional reaction vessel such as an autoclave, and when it is carried out in a bulk molten state, an extruder equipped with a devolatilization device may be used.

The temperature of the imidization reaction is about 80 to 350°C, preferably 100 to 300°C. If the temperature is lower than 80°C, the reaction rate is slow and the reaction takes a long time, which is not practical. On the other hand, if the temperature exceeds 350°C, the physical properties will deteriorate due to thermal decomposition of the polymer.

The imidized copolymer of maleic anhydride copolymer produced by the method described above maintains a high heat distortion temperature, has high stability against water and heat, and has impact resistance. It also has excellent properties and moldability.

This imidized copolymer is styrene-acrylonitrile copolymer (SA N tl resin), acrylonitrile-butadiene-styrene copolymer (A B S + flt
Acrylonitrile-butadiene-styrene-α-methylstyrene copolymer, acrylonitrile-acrylic rubber-styrene copolymer, acrylonitrile-ethylenepropylene rubber-styrene copolymer, styrene-methyl methacrylate copolymer, methyl methacrylate copolymer butadiene-styrene copolymer, aromatic polycarbonate, aromatic polyester, polyphenylene oxide, do,
It can also be mixed with styrene-modified polyphenylene oxide, etc. In particular, a mixture with ABS resin is preferred in terms of impact resistance and moldability. Furthermore, stabilizers, flame retardants, plasticizers, lubricants, fillers, colorants, etc. can also be added.

(Example) The present invention will be described below with reference to Examples, but the present invention is not limited thereto. All parts and percentages in the examples are expressed on a weight basis unless otherwise specified.

Example 1 Styrene (hereinafter St) was placed in an autoclave equipped with a stirrer.
) 60 parts, methyl ethyl ketone (hereinafter abbreviated as MEK)
30 parts of polybutadiene cut into small pieces (Diene NF35R, manufactured by Asahi Kasei Corporation) were charged, and after purging the system with nitrogen gas, the mixture was stirred at room temperature all day and night to dissolve the rubber. After setting the temperature to 80°C, maleic anhydride (hereinafter MA
! -! abbreviated) 40 parts and benzoyl peroxide 0.0
9 parts and 0.09 parts of azobisisobutyronitrile in MEK.
A solution of 250 parts was added continuously over 8 hours.

The viscosity of the polymerization solution was measured by the falling speed of the injection needle. The viscosity increased with the start of addition of the MAH solution, reached a maximum value at 2 hours, then decreased, became a minimal liquid at 2.5 hours, and then gradually increased over time.

This confirmed the phase transition.

Five hours after the start of the addition, a solution of 3 parts of polybutadiene dissolved in 50 parts of toluene was added over about 10 minutes. M
After the addition of the AH solution was complete, the temperature was maintained at 80° C. for an additional 4 hours. A portion of the viscous reaction solution was sampled and the amount of unreacted monomer was determined by gas chromatography to determine the polymerization rate, which was found to be 5t96% and MAH99%.

To this polymerization solution, 37 parts of aniline and 1 part of triethylamine were added and reacted at 140°C for 7 hours. The reaction solution was cooled to 90° C., poured into 1000 parts of vigorously stirred methanol, precipitated, filtered, and dried to obtain an imidized copolymer. C-
Analysis of C-13 showed that the conversion rate of acid anhydride groups to imide groups was 96%.

60 parts of the imidized copolymer thus obtained and acrylonitrile-styrene based sealant (manufactured by Denki Kagaku Kogyo @,
40 parts of H3-300) were blended, and this blend was extruded using a screw extruder equipped with a devolatilization device to pelletize. Tristearylphosphite 1 in the blend
part and 0.3 part of octadecyl 3-(35-ditertiarybutyl-4-hydroxyphenyl)-propionate.

Example 2 The same operation as in Example 1 was carried out, except that the toluene solution of polybutadiene was added over a period of 10 minutes immediately after the addition of the MAR solution.

The measurement results of the polymerization rate by gas chromatography are S,
t was 97% and MΔH was 99.5%. C-C-13
The conversion rate of acid anhydride groups to imide groups was 94% by partial analysis.
Met.

Example 3 The same procedure was carried out except that 40 parts of St and 10 parts of polybutadiene were charged into the autoclave, and a solution of 5 parts of polybutadiene dissolved in 20 parts of 5t was continuously added over 4 hours from 4 hours after the start of addition of the MAH solution. The same operation as in Example 1 was performed.

The measurement result of the polymerization rate by gas chromatography is 5t.
95%, MAH 98.5%. The conversion rate of acid anhydride groups to imide groups was 97% by CC-13 moiety analysis.

Comparative Example 1 As in Example 1, 60 parts of 5t, 30 parts of VER, and 15 parts of polybutadiene were charged, and after replacing the inside of the system with nitrogen gas,
The mixture was stirred at room temperature overnight to dissolve the rubber. After setting the temperature to 80°C, 40 parts of MAH and 0.0 parts of Penn Soil peroxide were added.
A solution of 0.09 part of azobisisobutyronitrile dissolved in 250 parts of MEK was continuously added over 8 hours. After the addition was complete, the temperature was maintained at 80° C. for an additional 4 hours.

The subsequent operations are the same as in the first embodiment.

The measurement result of the polymerization rate by gas chromatography is 5t.
It was 95% MAH 99%. The conversion rate of acid anhydride groups to imide groups was 96% by C-C-13 moiety analysis.

Example 4 In the same manner as in Example 1, 55 parts of 5t, 10 parts of acrylonitrile, 50 parts of MEK, and 1 part of polybutadiene were placed in an autoclave.
After charging 0 parts and replacing the inside of the system with nitrogen gas, the rubber was dissolved by stirring at room temperature all day and night. After setting the temperature to 80℃,
MAH35i and 0.06 part of benzoyl peroxide,
Add 0.12 parts of azobisisobutyronitrile to MEK2
A solution of 50 parts was added continuously over a period of 8 hours. Four hours after the start of addition, phase transition was confirmed in the same manner as in Example 1, and then a solution of 8 parts of polybutadiene dissolved in 70 parts of toluene was continuously added over 4 hours. The temperature was maintained at 80° C. for an additional 4 hours after the addition. From the quantitative determination of unreacted monomers, the polymerization rate was 5t99%, MAH98%, acryloni l-
IJ was 90%. Aniline 32.4 was added to this polymerization solution.
1 part of triethylamine were added thereto, and the mixture was reacted at 140°C for 7 hours. The conversion rate of acid anhydride groups to imide groups was 97%. After this, the same operations as in Example 1 were performed.

Comparative Example 2 The same operation as in Example 4 was carried out except that 18 parts of polybutadiene was charged into the autoclave and no toluene solution of polybutadiene was added.

The physical properties of the composition obtained as described above were measured and the first
Shown in the table.

As shown in Table 1, the thermoplastic resin obtained by the production method of the present invention exhibits significant improvements in impact strength and fluidity during molding without deteriorating the conventional thermal stability, heat resistance, and hot water resistance.

The physical properties were measured by the following method.

(1) Impact strength: Izot impact strength with notches.

According to ASTM D 256.

(2) VIFI (melt flow index)...Temperature 270℃, load 5kg, ASTM D-1238
According to.

(3) Thermal stability: Nitrogen flow 50cc/min, heating rate 1
Weight of polymer in thermobalance analysis at 0°C/min condition ff1
The temperature is shown when the N content is 1%.

(4) VSP (Vicat Softening Point)...load 5 kg,
According to AST D-1525.

(5) Hot water resistance: A notched isot test piece according to ASTM D-256 was immersed in hot water at 100°C for 24 hours, and the retention rate of the measured impact value (1) was shown.

Claims (1)

[Claims] 5 to 40 parts by weight of graft polymerizable elastomer, 50 to 90% by weight of aromatic vinyl monomer, 5 to 40% by weight of unsaturated dicarboxylic acid anhydride, and 0 to 30% by weight of vinyl monomer copolymerizable with these. A monomer mixture consisting of 60 to 95
In a method of producing a thermoplastic resin by graft polymerizing parts by weight and then imidizing with ammonia and/or a primary amine, 10 to 90% by weight of the total amount of elastomer used in graft polymerization is added before phase inversion. death,
A method for producing a thermoplastic resin, which comprises adding the remaining 90 to 10% by weight of an elastomer after phase inversion to perform graft polymerization.