JPS5921331B2 - Manufacturing method of high nitrile resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides high ethylenically unsaturated nitrile content.
Moreover, it relates to a method for producing a high nitrile resin reinforced with a rubber component.

More specifically, when graft polymerizing a monomer mixture containing an ethylenically unsaturated nitrile in the presence of a rubber component, the content of ethylenically unsaturated nitrile in the grafted resin portion is higher than that of the rubber component in the final polymer. The content of ethylenically unsaturated nitrile in the matrix resin part (excluding the initial rubber component in the polymer after graft polymerization) is higher than the content of ethylenically unsaturated nitrile in the final polymer rubber. It is a non-uniform polymer composition whose content is lower than the content of ethylenically unsaturated nitrile in the parts other than the components, and has high impact strength, good processability, and excellent solvent resistance. The present invention relates to obtaining polymer compositions. So-called nitrile resins with a high proportion of ethylenically unsaturated nitrile units have excellent gas barrier properties and solvent resistance, and are recognized for their practical value in the fields of packaging materials and industrial materials. In particular, rubber-reinforced copolymers of ethylenically unsaturated nitrile and aromatic vinyl compounds are known to have high heat distortion temperatures, further increasing their usefulness; ] In the production of copolymers of biounsaturated nitrile and aromatic vinyl compounds, due to the marked difference in radical polymerizability between the two, in the usual radical polymerization method, the composition ratio of the produced polymer differs between the early and late stages of polymerization. Because of these differences, the resulting resin becomes non-uniform, resulting in decreased impact resistance and thermal stability. This is because when an ethylenically unsaturated nitrile and an aromatic vinyl compound are charged and polymerized using a conventional method, in the initial stage of polymerization, the highly reactive aromatic vinyl is present in a copolymer containing a higher proportion than the charged composition. This is because coalescence is obtained, and on the other hand, in the late stage of polymerization, an ethylenically unsaturated nitrile polymer is produced. For this reason, various proposals have been made regarding methods for producing copolymers or rubber-reinforced copolymers of ethylenically unsaturated nitrile and aromatic vinyl compounds having highly uniform compositions. For example, the special public service
No. 574 is an ethylenically unsaturated nitrile compound in the presence of a diene rubber. In copolymerizing acrylonitrile and an aromatic vinyl compound, a highly reactive aromatic vinyl compound is added at a rate that keeps the reflux temperature constant. A method of obtaining a copolymer with a uniform composition at a moderate yield by monitoring the monomer composition with a gas chromatograph as the polymerization progresses and adding monomer to keep the composition constant;
Alternatively, Japanese Patent Publication No. 49-1950 describes a method in which an aromatic vinyl compound having a high reaction rate is added in accordance with the heat generated by polymerization. In all of the above proposed methods, the monomer composition is adjusted in advance so as to obtain a copolymer with the desired composition, and the monomer composition in the polymerization system is adjusted while monitoring the progress of the charging polymerization. By adding a portion of the monomer to keep it constant, a copolymer with a highly uniform composition is obtained. However, in these methods, a large amount of monomer is initially charged into the polymerization system, making it difficult to remove the polymerization heat, the degree of polymerization progress must be constantly monitored, and the amount of monomer must be adjusted as the polymerization progresses. There are problems in that the addition of polymers must be adjusted, and in order to obtain a polymer with a uniform composition, the polymerization operation and equipment must be complicated. The liquidity is extremely unsatisfactory. As a result of intensive research by the present inventors,
When polymerizing ethylenically unsaturated nitrile in the presence of rubber, by making the composition of the graft resin part and the composition of the matrix resin part non-uniform, it is possible to improve solvent resistance without impairing processing fluidity and impact resistance. They succeeded in significantly improving their sexual performance.

That is, in the presence of 5 to 20 parts by weight of a rubber containing 50% by weight or more of a 1,3-conjugated diene, monomers consisting of an ethylenically unsaturated nitrile, an aromatic vinyl compound, and an alkyl methacrylate and/or an alkyl acrylate. 80 to 95 parts by weight of the copolymer was graft-polymerized to obtain 100 parts by weight of the copolymer.
In the parts by weight, (4) 2 to 40 parts by weight of a grafted resin portion consisting of an ethylenically unsaturated nitrile and an aromatic vinyl compound grafted to the rubber, and optionally an alkyl methacrylate and/or an alkyl acrylate; (B) an ethylenic resin; Consisting of 40 to 93 parts by weight of a matrix resin portion consisting of unsaturated nitrile and aromatic vinyl compounds and alkyl methacrylate and/or alkyl acrylate, (
The range between X weight% of the ethylenically unsaturated nitrile component in A) and Y weight% of the ethylenically unsaturated nitrile component in (B) is 45≦Y<X, and 60≦X≦ The subject matter is a method for producing a high-toleryl-based resin that satisfies 85.

In addition, the graft resin part as used in the present invention is a polymer part corresponding to a branch where a monomer is graft copolymerized to rubber, and among the components separated as acetonitrile-insoluble parts, excluding the rubber part corresponding to the initial trunk. The matrix resin portion is separated from the acetonitrile soluble portion.

A particularly important point in the present invention is that the content of unsaturated nitrile polymerized in the graft resin portion is relatively high.

In other words, it was discovered that having a higher unsaturated nitrile content in the grafted resin part than in parts other than the rubber component of the final polymer not only improves solvent resistance but also significantly reduces weight. It is ivy. Next, the present invention will be explained in detail.

The rubber containing 1,3 conjugated diene used in the present invention is a homopolymer of 1,3 conjugated diene or at least 5
It is a copolymer of 0% by weight of 1.3 conjugated diene and a vinyl monomer that can be copolymerized with this.

Examples of 1,3 conjugated dienes include 1,3 butadiene, isoprene, and chloroprene.

Monomers copolymerizable with the 1,3-conjugated diene monomer include styrene, substituted styrene, α-methylstyrene, substituted α-methylstyrene, acrylonitrile, or alkyl groups such as methyl, ethyl, propyl, and n-butyl. There are alkyl acrylates, alkyl methacrylates, etc., which have the following, and these can be used alone or in combination.

Further, a crosslinked structure may be imparted to the diene rubber by copolymerizing a polyfunctional monomer such as divinylbenzene, polyethylene glycol dimethacrylate, or allyl acrylate. Such a 1,3-conjugated diene polymer needs to contain at least 50% by weight of diene units.

That is, when the 1,3-conjugated diene content is less than 50% by weight, the glass transition temperature of the rubber increases, making it impossible to improve the impact resistance of the final polymer. Further, the above-mentioned 1,3-conjugated diene polymer can be produced by various well-known methods. That is, any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be used, but emulsion polymerization is particularly preferable, and the average particle diameter of the diene rubber latex is 0.00000000000000000000000000000000000000000000000000000000000,000.
It is preferably in the range of 0.05 to 0.2μ, but is not particularly limited. The high nitrile resin of the present invention is obtained by polymerizing ethylenically unsaturated nitrile, aromatic vinyl compound, and alkyl methacrylate and/or alkyl acrylate in the presence of the diene polymer produced in advance as described above. You can get it. Examples of the ethylenically unsaturated nitrile include acrylonitrile and methacrylonitrile, with acrylonitrile being preferred. Examples of aromatic vinyl compounds include styrene, substituted styrene, α-methylstyrene, substituted α-methylstyrene, and the like, with styrene being the most representative. The alkino groups in alkyl acrylates and alkyl methacrylates include methyl, ethyl, propyl, n-butyl, etc., with methyl group being the most representative. The use of alkyl methacrylate and/or alkyl acrylate improves the balance between processing fluidity and impact resistance of the high nitrile resin obtained in the present invention. Monomers other than the ethylenically unsaturated nitrile, that is, aromatic vinyl compounds, alkyl methacrylates, and alkyl acrylates, are substituted with other copolymerizable vinyl compounds, such as vinyl esters and vinyl ethers, to the extent that physical properties are not impaired. It's okay. In this case, the amount of substitution is up to 30% by weight of the total of vinyl compounds other than ethylenically unsaturated nitrile, that is, aromatic vinyl compounds, alkyl methacrylates, and alkyl acrylates. The composition of the graft resin part is such that the ethylenically unsaturated nitrile content X is from 60 to
85% by weight, and 40 to 15% by weight of other vinyl monomers.

When the amount of ethylenically unsaturated nitrile is less than 60% by weight, chemical resistance is not improved, and when it is more than 85% by weight, processability becomes poor, and the thermal stability of the final resin composition during molding becomes poor, i.e., it becomes yellowish. The coloring becomes stronger. The composition of the matrix resin part is the ethylenically unsaturated nitrile content Y
is>X>Y≧45% by weight other vinyl monomer (1
00-Y)% by weight.

When the amount of ethylenically unsaturated nitrile is less than 45% by weight, problems occur in solvent resistance. Moreover, if this is the same as the ethylenically unsaturated nitrile content of the graft resin portion, processability is poor. Moreover, if the content of ethylenically unsaturated nitrile units is higher than the content of ethylenically unsaturated nitrile units in the graft resin portion, problems arise in solvent resistance. Further, it is preferable that the ethylenically unsaturated nitrile content of the graft resin portion and the matrix resin portion differ by 5% by weight or more.

In the method for producing the resin of the present invention, a monomer containing a high proportion of ethylenically unsaturated nitrile is first added, and then a monomer containing a small proportion of ethylenically unsaturated nitrile is added continuously or in multiple steps. By polymerizing by changing the monomer composition,
can also be manufactured. The amount of rubber component in the total resin is approximately 5 to 20 parts by weight per 100 parts by weight of resin.

This is because if the rubber content is less than 5 parts by weight, the impact resistance will be poor, and if the rubber content is extremely large, the gas barrier properties and solvent resistance will be poor.

The amount of polymer in the graft resin portion is 2 to 40 parts by weight, preferably 0.4 to 2 times the number of rubber parts.

If it is less than 2 parts by weight, solvent resistance will not be improved, and if it exceeds 40 parts by weight, processability will deteriorate.

In order to maintain impact resistance, the vinyl monomers in the graft resin portion and the matrix resin portion must be selected so as not to impair the compatibility of the two polymers. For this purpose, it is necessary that the aromatic vinyl compound unit be contained in both the graft resin part and the matrix resin part. In the present invention, the method of copolymerizing ethylenically unsaturated nitrile and vinyl monomer in the presence of a conjugated diene rubber can be carried out by well-known solution polymerization, bulk polymerization, emulsion polymerization, or a combination thereof. However, it is industrially advantageous to employ emulsion polymerization.

Further, in carrying out this emulsion polymerization, it is better to add a predetermined amount of monomer in portions or continuously to obtain better results in terms of impact resistance.

The latex obtained in this way is coagulated by a conventional method.
Wash with water, dry, add antioxidants, stabilizers, lubricants, or pigments as necessary, and perform calendar molding, blow molding, injection molding, or extrusion molding to make bottles, biaxially stretched bottles, and unstretched bottles. Films, uniaxially stretched films, biaxially stretched films, sheets, etc. can be made. The nitrile resin of the present invention obtained as described above has high fluidity and impact strength as well as excellent chemical resistance, and therefore has extremely high practical value. The present invention will be explained in more detail with reference to Examples below, but the invention is not limited by the Examples.

In the examples, "parts" and "%" are by weight unless otherwise specified. Example 1 (4) Production of diene-based rubber latex The above main and auxiliary raw materials were charged into a pressure-resistant closed polymerization vessel, and polymerization was carried out at 40°C for 10 hours while stirring and removing oxygen.

As a result, the polymerization conversion rate of the monomer was 98%, and the average particle diameter of the latex was 0.06μ as measured by an electron microscope.
It was hot. E. Production of nitrile resin The above substances were placed in a polymerization vessel, kept at 61°C for 1 hour while stirring in a nitrogen stream, and 0.07 part of potassium persulfate was added immediately to form a mixture with the first monomer composition shown in Table 1. 30
15 minutes after the addition of the first monomer mixture was completed, 40 parts of a mixture having the second monomer composition shown in the same table was continuously added over 5 hours. After the addition was completed, the polymerization was continued for another hour.

Potassium persulfate was additionally added at 0.02 part and 0.03 part at 3 hours and 5 hours after the start of addition of the first monomer mixture, respectively. After the polymerization was completed, the polymerized latex was cooled to 50 DEG C. or lower, coagulated with calcium chloride, and then heat-treated at 80 to 90 DEG C. The resulting white powdery resin was washed with water, filtered with P, separated, and dried.

The obtained dry powdered resin is dissolved in the solvent acetonitrile, and separated into a matrix resin part that is soluble in acetonitrile, a graft rubber part that has a graft resin part in which a monomer is grafted to acetonitrile-insoluble rubber, and a trunk rubber. The compositions of the matrix resin part and the graft resin part of the graft rubber part were investigated by elemental analysis. Additionally, 0.5 parts of di-t-butyl hydroxytoluene was added to 100 parts of this powdered resin, pelletized using a vented extruder, and made into a bag-shaped sample for Izot impact strength measurement using a 3-ounce injection molding machine. was molded and the Izod impact strength at 23°C was measured. In addition, to examine the processability of the resin, we used a Koka type flow tester (manufactured by Shimadzu Corporation).
220℃ under load condition of 100kg/Cd, diameter 1m
The flow rate of the polymer *× from a nozzle with a length of m1 of 10 mm was measured, and the fluidity index (FI) was calculated. In addition, to test solvent resistance, ASTM molded with a 3-ounce injection molder.
Using a tamper-shaped sample of No. 1, a 2-week immersion test was conducted in xylene at 40°C, and changes in the test piece were observed with the naked eye. The results are shown in Table 1 for Experimental Waterfall 1,
Shown in 2, 3, and 4. Comparative Example 1 (Experiment/165, 6 in Table 1) The same procedure as in Example 1 was carried out except that the monomer composition additionally added during graft polymerization was carried out according to Experiments 5 and 6 in Table 1.

As can be seen from the physical properties of the polymer shown in Table 1, the resin produced by the present invention has excellent solvent resistance and processability as indicated by FI, but the solvent resistance of the comparative example is poor. It can be seen that the processability is poor. Example 2 The rubber synthesized in Example 1 was used in the following manner.

The above materials were charged into a polymerization container, kept at 61°C with stirring in a nitrogen stream, and left for 1 hour, followed by 0% potassium persulfate.
Add 10 parts ANl, 2 parts STl. Part 8, MMA1. 2
part and n-DMl. 1 part of the mixed solution was added continuously over 1 hour, and then the second stage mixed monomers (44 parts of AN, S
3.8 parts of Tl and 9.2 parts of MMA) were continuously added over 7.5 hours.

(However, 1.1 parts of n-DM was added to the 15 parts added first out of 67 parts of the second monomer, and 0.02 parts of potassium persulfate was added 4 hours after the start of addition of the first monomer. ) About 1 hour after the addition of the second monomer was completed, polymerization was carried out and the mixture was cooled, and the post-treatment was carried out in the same manner as in Example 1-(B). The results are shown in Table 2. Comparative Example 2 An experiment was conducted in the same manner as in Example 2 except for the following points.
Only 15 copies were added and no additions were made midway through.

Also, the method of adding monomers was changed as follows. That is, AN
56 parts, 5.6 parts of STl, MMAIO. Add 2.2 parts of n-DM to 30 parts of the 4 parts mixed monomer solution 2
The remaining 52 parts were added over 6 hours and postpolymerized for 1 hour before cooling. The results are shown in Table-2. Comparative Example 2, which had a uniform composition, had poor processing fluidity and could not even be molded as a sample.

Therefore, it can be seen that the resin produced according to the present invention has excellent fluidity and chemical resistance. In addition, when similar polymerization was carried out using 5.0 parts of n-DM instead of 2.2 parts in Comparative Example 2,
Although the FI was 0.8, it had a strong mercaptan odor and was of no practical value. In addition, due to the excessive use of mercaptan, the molecular weight decreased and the solvent resistance decreased, resulting in whitening and devitrification in the solvent resistance test using ASTM No. 1 tamper. Example 3 The same procedure as Example 2 was carried out except that the composition of the monomers added was changed.

First monomer (ANlO.O part, ST3.O part, MMA
2. Part O, n-DMl. 1 part) was added continuously over 1 hour, and then the second monomer (35 parts AN, 9 parts STl, 3 parts MMAl) was added continuously over 7.5 hours. (However, 1.1 part of n-DM was added to the 15 parts added first out of 67 parts of the second monomer. Also, 0.02 part of potassium persulfate was added 4 hours after starting the first monomer.
) After about 1 hour after the addition of the second monomer was completed, polymerization was carried out and the mixture was cooled, and the post-treatment was carried out in the same manner. The results are shown in Table-3. Comparative example
3 The same procedure as in Comparative Example 2 was carried out except that the composition of the monomers added was changed.

Add 2.2 parts of n-DM to 3.0 parts of a mixed monomer solution of 45 parts AN, 22 parts ST, and 5 parts MMAl and continuously add it over 2 hours, and add the remaining 52 parts over 6 hours. After polymerization was carried out for 1 hour, the mixture was cooled, and the post-treatment was carried out in the same manner. The results are shown in Table-3. Comparative example 3 with uniform composition
Although molding was possible, the resin had poor solvent resistance and whitened, whereas the resin produced according to the present invention does not whiten and has excellent chemical resistance.

Example 4 Example 1 except that 20 parts of acrylonitrile was replaced with a mixed monomer of 16 parts of acrylonitrile, 0.6 parts of styrene, and 0.4 parts of methyl methacrylate.
- Rubber etc. were prepared in the same manner as in (B), and the method of adding monomer was changed.

First stage mixed monomer (ANlO part, ST3.O part, M
MA2. Part O, n-DMl. 2 parts) was added continuously for an hour or so, followed by the second stage mixed monomers (34 parts AN,
STl2. O5. MMAAl2. Part O) was continuously added over 6.5 hours (however, 1.2 parts of NDM was added to the 15 parts added first out of 58 parts of the second monomer).

Approximately 1 hour after the addition of the second monomer was completed, polymerization was carried out and the mixture was cooled, and the post-treatment was carried out in the same manner. The composition of the graft resin part is (AN
75. OOA). (STl 5.5%, MMA 9.5%) and the composition of the matrix resin part is AN63.6%, STl
8.4%, MMA17.9%, FI is 1.2, IzOd
7.8, there was no change in chemical resistance. Thus, by graft polymerizing according to the present invention to obtain a polymer containing a specific amount of specified components, a useful high nitrile polymer having excellent solvent resistance without impairing fluidity and impact resistance can be obtained. Compositions are provided.

Claims (1)

[Scope of Claims] 1. A monomer consisting of an ethylenically unsaturated nitrile, an aromatic vinyl compound, and an alkyl methacrylate and/or an alkyl acrylate in the presence of 5 to 20 parts by weight of a rubber containing 1,3 conjugated diene in an amount of 50% by weight or more. In 100 parts by weight of the polymer, (A) an ethylenically unsaturated nitrile and an aromatic vinyl compound grafted onto the rubber, and optionally an alkyl methacrylate and/or an alkyl acrylate. Graft resin part consists of 2 to 40 parts by weight (B) Matrix resin part consisting of ethylenically unsaturated nitrile and aromatic vinyl compound and alkyl methacrylate and or alkyl acrylate consists of 40 to 93 parts by weight, and occupies in (A) The ratio between the ethylenically unsaturated nitrile component X weight % and the ethylenically unsaturated nitrile component Y weight % in (B) satisfies 45≦Y<X and 60≦X≦85. A method for producing high nitrile resin characterized by: 2. The method for producing a high nitrile resin according to claim 1, wherein the ethylenically unsaturated nitrile is acrylonitrile. 3. The method for producing a high nitrile resin according to claim 1 or 2, wherein the aromatic vinyl compound is styrene. 4. The method for producing a high nitrile resin according to claim 1, 2 or 3, wherein the alkyl methacrylate is methyl methacrylate.