JPS595139B2 - Acrylonitrile resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas-impermeable acrylonitrile resin composition for molding that has excellent alcohol resistance, impact resistance, and transparency.

In recent years, molding acrylonitrile resins containing a high proportion of acrylonitrile have gas impermeability, water vapor impermeability, and impact resistance, so they have been used for food packaging films, carbonated beverages, alcoholic beverages, foods, and cosmetics. It is becoming widely used for containers, etc.

Such acrylonitrile-based resins include acrylic acid alkyl esters or methacrylic acid alkyl esters having 70% by weight or more of acrylonitrile and an alkyl group with a small number of carbon atoms (1 to 6 carbon atoms) in the presence of a diene-based rubbery polymer. A graft obtained by mixing a graft copolymer obtained by graft polymerizing a monomer mixture consisting of 30% by weight or less of at least one of the above with a resinous polymer obtained by copolymerizing the monomer mixture. - Blend type resin compositions (for example, Japanese Patent Publication No. 49-13853) are known.

In addition, a similar graft-blend type resin composition is disclosed in Japanese Patent Application Laid-open No. 4
8-791. However, the graft-blend acrylonitrile resins produced by these methods have poor water resistance and alcohol resistance, so when used in applications where they come into contact with contents containing water and/or alcohol, they may become cloudy. This phenomenon is further accelerated at high temperatures, and has the disadvantage of significantly reducing commercial value. Conventionally, as a method for improving water resistance, a method has been proposed in which octyl acrylate is added as a component of the monomer mixture and polymerized (Japanese Patent Publication No. 4921105), but although these methods improve water resistance, No alcoholic improvement was observed.

In other words, improving the alcohol resistance of acrylonitrile resins is not achieved by simply imparting water resistance to the acrylonitrile polymer, but rather by imparting alcohol resistance properties in addition to water resistance. There is a need to.

Therefore, an object of the present invention is to provide a gas-impermeable acrylonitrile resin composition with improved alcohol resistance.

The acrylonitrile resin composition of the present invention that achieves the object of the present invention comprises the following components (4) and (B):
This is a mixture obtained by mixing the diene rubber-like polymer in the resulting composition [(4)+(B)] so that the content thereof is 3 to 20% by weight.

Component (A): 60 to 90% by weight of acrylonitrile, preferably 65 to 85% by weight, and 1 to 35% by weight of at least one selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having an alkyl group having 1 to 6 carbon atoms. %, preferably 5 to 30% by weight and methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms 0
．． A resinous copolymer obtained by polymerizing a monomer mixture comprising 5 to 15% by weight, preferably 1 to 10% by weight.

Component (B): Diene-based rubbery polymer 2 consisting of 50% by weight or more of conjugated diene and 50% by weight or less of acrylonitrile
60% by weight of acrylonitrile in the presence of 0 to 60 parts by weight
an amount exceeding 90% by weight, 1 to 35% by weight of at least one selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having an alkyl group having 1 to 6 carbon atoms, and an alkyl group having 12 to 18 carbon atoms. methacrylic acid alkyl ester with O to 15% by weight, preferably O
A graft copolymer obtained by polymerizing 40 to 80 parts by weight of a monomer mixture comprising up to 10% by weight.

In the present invention, a methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms, which is one of the monomers constituting the resinous copolymer (4), is added to the graft-blend type acrylonitrile resin composition. It is an important component essential for imparting alcohol resistance and improving transparency.

According to a light transmittance test, the effect of the methacrylic acid alkyl ester on alcohol resistance improves as the number of carbon atoms in the alkyl group increases among 12 to 18 carbon atoms; Hard to judge. When the methacrylic acid alkyl ester is replaced with an acrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms, no improvement in alcohol resistance is observed and transparency is reduced. The amount of methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms is 0.5 based on the total monomers used to produce component (8).
The effect is recognized when the amount is more than 15% by weight, and the alcohol resistance improves further as the amount increases, but even when more than 15% by weight is used, the degree of improvement reaches saturation, and peeling phenomenon etc. occur in the melt-molded product. Hail! For these reasons, the proportion of the methacrylic acid alkyl ester having an alkyl group of Cl2 to 18 is 0.5 to 15% by weight, preferably 1 to 10% by weight, and more preferably 1 to 5% by weight. The alcohol resistance and transparency of the composition of the present invention can be greatly improved by including a methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms as a constituent component of the resinous copolymer (4). However, when it is desired to further enhance such characteristics, the methacrylic acid alkyl ester is added as a graft monomer component when producing the graft copolymer (8). The amount added is up to 15% by weight, preferably up to 10% by weight, and more preferably from 1 to 5% by weight, based on the total monomers to be grafted. If 15% by weight or more is used, the effect reaches saturation and is also disadvantageous from an economical point of view.

In addition, the ratio of the diene rubber-like polymer and the graft monomer obtained by graft polymerization thereto is from 20 to 60:80.
40 (parts by weight). If the proportion of the rubbery polymer is 60 parts by weight or more, the surface gloss of the molded product will decrease, and if it is less than 20 parts by weight, processability will decrease (deterioration of flow characteristics due to increased viscosity during molding). Defects appear.
The mixing ratio of component (4) and formation B) is (4)+(B)
) containing 3 to 20 diene rubber-like polymers in the composition.
% by weight, preferably from 5 to 20% by weight.

Even if the proportion of the diene-based rubbery polymer exceeds 20% by weight, the improvement in impact resistance reaches saturation and gas impermeability decreases, which is not preferable. The diene-based rubbery copolymer used in the present invention contains 50% by weight or more of conjugated diene units such as butadiene or isobrene, preferably 70 to 100% by weight.
% by weight, more preferably 70-95% by weight and less than 50% by weight of acrylonitrile units, preferably 0-30% by weight
More preferably, it is a diene-based rubbery copolymer containing 5 to 30% by weight.

If the amount of acrylonitrile used is 50% by weight or more, this is not preferable because the impact resistance of the resulting resin composition will decrease. In addition, diene-based rubbery copolymers are used to improve the impact resistance of resin compositions, especially at low temperatures.
) is preferred. Carbon number used in the present invention is 1 or more
Examples of acrylic acid alkyl esters and methacrylic acid alkyl esters having 6 alkyl groups include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. etc.

Examples of the methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms include lauryl methacrylate, dodecyl methacrylate, myristyl methacrylate, cetyl methacrylate, and stearyl methacrylate. The resinous copolymer (4) can be produced by any known bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization method, etc., but the O-graft copolymer B) is preferably produced by an emulsion polymerization method. It can be produced by using an emulsified latex-like diene rubber-like polymer, adding a graft monomer, and carrying out graft polymerization according to a known method.

The polymerization initiators used in the production of the above components (4) and (B) of the present invention include commonly used potassium persulfate, ammonium persulfate, hydrogen peroxide, benzoyl peroxide, tert-butyl peroxyhyparate, etc. organic or inorganic peroxides, azo free radical generators such as azobisisobutyronitrile, and redox initiators that are a combination of water-soluble peroxides and reducing agents. Surfactants such as fatty acids, rosin acids, alkali metal salts of alkylbenzenesulfonic acids, sulfuric ester alkali metal salts, and phosphoric esters of higher aliphatic alcohols are used. Further, these polymerizations can be carried out by a batch method in which the monomer mixture and other components involved in the copolymerization are added continuously or intermittently. The resinous copolymer (4) and the graft copolymer (B) may be mixed by either dry blending or latex blending. The thus obtained graft-blend resin composition of the present invention has better processability (
It has favorable properties such as good flow during melting, excellent color tone, and low basis weight during blow pin molding. The present invention will be explained below by way of examples.

All parts and percentages in the examples are based on weight unless otherwise specified. Example 1 (1) Production of diene-based rubbery polymer latex Polymerization recipe for rubbery polymer All of the above polymerization recipe except CHP was placed in an autoclave and the temperature of the reaction system was adjusted to 5°C under a nitrogen atmosphere. Thereafter, CHP was added to the system and the reaction was completed while stirring for 20 hours (the conversion rate of the monomer mixture was 97%).

), a good acrylonitrile-butadiene rubbery copolymer (NBR) latex was obtained. When observed by electron micrograph, the rubbery polymer in the latex was found to be uniformly sized particles with an average particle size of 0.1 μm.

This acrylonitrile-butadiene rubbery copolymer latex is used in the preparation of graft copolymers in the following examples. (Ii) Preparation of resinous polymer (4) 100 parts of the monomer mixture shown in Table 1, 1.
5 parts of sodium lauryl sulfate, 0.8 parts of sodium pyrophosphate anhydride, 0.2 parts of anhydrous sodium pyrophosphate, 0.08 parts of potassium persulfate, and 200 parts of water were placed in an autoclave and polymerized at 55°C for 16 hours while stirring under a nitrogen atmosphere. A good resinous copolymer latex was obtained.

The final conversion of the monomer mixture is shown in Table 1. (iii)
Preparation of graft copolymer (B) 100 parts of the monomer mixture shown in Table 2, 10 parts of the acrylonitrile-butadiene rubbery copolymer (as solid content in latex) of (1) above.
0 parts, 0.3 parts of t-dodecyl mercaptan, 0.8 parts of sodium lauryl sulfate, 0.2 parts of anhydrous sodium pyrophosphate, 0.08 parts of potassium persulfate, and 600 parts of water were placed in an autoclave and stirred under a nitrogen atmosphere. 16 at 55℃ while
Time polymerization was carried out to obtain a good graft copolymer latex.

The final conversion of the monomer mixture is shown in Table 2. 0V) Graft type f-crylonitrile resin B-(4
) 75 parts of acrylonitrile, methyl acrylate
100 parts of a monomer mixture consisting of 220 parts and 5 parts of lauryl methacrylate, and the acrylonitrile-butadiene rubbery copolymer of (1) above (as solid content in the latex).
15 parts of t-dodecyl mercaptan, 1.5 parts of sodium laurate, 0.8 parts of sodium laurate, 0.2 parts of sodium pyrophosphate free dihydrate, 0.08 parts of potassium persulfate, and 345 parts of water were placed in an autoclave, and the mixture was heated under a nitrogen atmosphere. Polymerization was carried out at 55° C. for 16 hours with constant stirring, and a good polymer latex was obtained with a final conversion of 95% (ratio of rubbery copolymer/graft monomer mixture = 13/87).

(V) By combining the above-mentioned (Ii) resinous polymer (4) latex and (11) graft copolymer (B) latex shown in Table 3, the rubber-like polymer in the resulting resin composition is obtained. The content of the polymers was adjusted to 13% by weight and mixed, and the graft polymer B-(4) (0V) was used alone, and the weight of each latex was salted with a 0.4% aluminum sulfate aqueous solution. After washing with Sawabetsu water, a white powder polymer was obtained by drying at 60° C. for 48 hours.
The thus obtained white powdery polymer was melt-kneaded for 3 minutes with a heated roll at 160'C to make a roll sheet, which was preheated with a 170°C hot press for 5 minutes, pressed for 5 minutes, and then cooled. A 1 mm sheet with a glossy surface was produced.

Next, the alcohol resistance of each press sheet was tested using the following method. Chemical resistance test Based on ASTM D54367, the sheet was immersed in a 50% ethyl alcohol aqueous solution adjusted to 50°C for 30 hours, and the sheet before and after immersion was rated according to JIS standards.
Parallel light transmittance was measured based on the K67l4 test method.

In order to see the rate of decrease in parallel light transmittance before and after dipping, the ratio of parallel light transmittance before and after dipping was expressed as a percentage.

Regarding impact strength, JIS-K-6911-1962
A test piece specified in the above was prepared, and the notched Izot impact strength at 23°C was determined.

Regarding oxygen permeability, a 0.02 mm film was made from the polymer using the inflation method, and ASTMD14
Measurements were carried out based on the test method of No. 34-63. The results of these tests are summarized in Table 3.

The initial transparency of the sheet of Invention Example Black 1.2.3 was also good;
It can be seen that the light transmittance value after immersion in alcohol solution is also large, clearly showing excellent alcohol resistance.

The immersed sheets of the examples of the present invention were all transparent to the naked eye, and the difference could not be determined. However, the sheet of Comparative Example Black 5 before dipping had some cloudiness, and the sheet of Comparative Example Black 1, 2, 3, 4, and 5 after dipping clearly showed a decrease in the light transmittance value. , it appears cloudy to the naked eye and its transparency is significantly impaired.

(VO Next, (V) Graft-blend type resin composition of Invention Example Black 1 and (S) Mere graft type resin B (4)
The flow characteristics (processability) and color tone during melting were investigated.

The evaluation method is to produce pellets from each resin using an extruder heated to 180°C, and use a Koka type flow tester to measure the melt viscosity of 105 poise (under a 200k9/Cd load).
According to the temperature indicated.

The color tone was determined by measuring the yellowness of JlSK7lO3 using a reflected light method using an automatic colorimeter. The results are shown in Table 4. Example. 2 The monomer components in the resinous polymer A-(1) prepared in Example 1 were converted into acrylonitrile/hexyl methacrylate/
Polymer A-(7) was prepared in the same manner as A-(1) except that lauryl methacrylate (75/20/5) was used.
The same experiment as in Inventive Example 3 was carried out (Inventive Example 4) except that -(1) was used instead.

The results are shown in Table 5. Example 3 Graft copolymer B-(3) prepared in Example 1 was prepared in the same manner as B-{3) except that the graft monomer component was acrylonitrile/butyl methacrylate (75/25). An experiment similar to Inventive Example 3 was conducted except that Polymer B-(4) was used in place of B-(3) (Inventive Example 5).

Claims (1)

[Claims] 1 60-90% by weight of acrylonitrile and 1-6 carbon atoms
1 to 35% by weight of at least one selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having an alkyl group of
Resin-like copolymer (A) obtained by polymerizing a monomer mixture consisting of 5% by weight, a diene-based rubbery polymer 20 consisting of 50% by weight or less of conjugated diene units and 50% by weight or less of acrylonitrile units. Amount of acrylonitrile exceeding 60% by weight in the presence of ~60 parts by weight ~90% by weight and carbon number 1 ~
1 to 35% by weight of at least one selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having 6 alkyl groups, and 0 to 15% by weight of methacrylic acid alkyl esters having an alkyl group of 12 to 18 carbon atoms. A graft copolymer (B) obtained by polymerizing 40 to 80 parts by weight of a monomer mixture of A gas-impermeable acrylonitrile resin composition with excellent alcohol resistance, impact resistance, and transparency. 2 Acrylonitrile 65-85% by weight and carbon number 1-6
5 to 30% by weight of at least one selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having alkyl groups of
and a resinous polymer (A) obtained by polymerizing a monomer mixture consisting of 20 to 60 parts by weight of a diene-based rubbery polymer consisting of 50% by weight or more of conjugated diene units and 50% by weight or less of acrylonitrile units. Acrylonitrile 60 in the presence of
At least one type selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having an alkyl group having 1 to 6 carbon atoms and an amount exceeding 90% by weight
Graft copolymer (B) obtained by polymerizing 40 to 80 parts by weight of a monomer mixture consisting of 35% by weight and 0 to 10% by weight of a methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms. 2. The resin composition according to claim 1, which is obtained by mixing the following: such that the content of the diene rubber-like polymer in the resulting composition is 5 to 20% by weight. 3. The resin composition according to claim 1 or 2, wherein the acrylic acid alkyl ester is methyl acrylate. 4. The resin composition according to claim 1, 2 or 3, wherein the methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms is lauryl methacrylate. 5. The resin composition according to claim 1, 2 or 3, wherein the methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms is stearyl methacrylate. 6. The resin composition according to claim 1, 2, 3, 4, or 5, wherein the conjugated diene unit is butadiene. 7. Claims 1 and 2, wherein the diene rubbery polymer is an acrylonitrile-butadiene rubbery copolymer.
3. The resin composition according to item 3, item 4, or item 5.