JPS6065054A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide a thermoplastic resin compsn. having excellent coatability, processability, resistance to chemicals and impact, etc. and suitable for use as a coating material, by mixing a polycarbonate resin with a rubber-modified thermoplastic resin contg. an unsaturated nitrile as a component. CONSTITUTION:A monomer mixture contg. an unsaturated nitrile such as acrylonitrile is polymerized in the presence of a rubber polymer such as polybutadien to such an extent that 30-70wt% (including 0-20wt% unsaturated nitrile) of the monomer mixture is polymerized. The remaining monomer mixture having an unsaturated nitrile monomer content of 35-90wt% is polymerized to prepare a rubber-modified thermoplastic resin wherein the content of the unsaturated nitrile in the polymerized mononer moiety is 28-38wt%. 80-10wt% said rubber-modified thermoplastic resin is mixed with 20-90wt% polycarbonate to obtain the desired thermoplastic resin compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel polycarbonate resin composition with improved paintability, more specifically, it has high chemical resistance, excellent paintability, impact resistance and processability. Good?
The present invention relates to a composition of a recarbonate resin and a rubber-modified thermoplastic polymer.

Polycarnate resin is an engineering plastic with high heat resistance and is widely used in various fields. Conventionally, methods for improving the processability and chemical resistance of precarnate resins and imparting high impact resistance include rubber, ABS resin, and MBS resin, which are types of modified thermoplastic resins. It has been proposed to use a blend of

In addition, in recent years, as exterior materials for automobiles and light electrical equipment that require heat resistance, materials that have undergone secondary processing through painting to improve aesthetics and weather resistance have been desired, and polycargonate resin and rubber-modified thermoplastic Although progress has been made to use compositions comprising resins for such purposes, various problems have arisen.

In general, rubber-modified thermoplastic resins such as ABS resin and MBS resin have good adhesion with paints and affinity with thinners, so they have excellent paintability. The molded item is painted.

However, with compositions of polycarbonate resin and rubber-modified thermoplastic resin, poor paintability has become a problem, and this is due to the poor chemical resistance of polycarbonate resin. Conventional compositions tend to cause defects such as stress cracks, and in the automotive field, there are defects such as lifting of the paint film (paint peeling) when solvents such as gasoline adhere to the painted surface. Sexuality is not fully satisfied.

Therefore, the present inventors conducted intensive studies to utilize the excellent properties of the composition of polycargonate resin and comb-modified thermoplastic resin and to improve the paintability, and finally arrived at the present invention.

The purpose of the present invention is to have high chemical resistance and excellent paintability.
Another object of the present invention is to provide a thermoplastic resin composition having good impact resistance and processability.

That is, the thermoplastic resin composition of the present invention first contains an unsaturated nitrile monomer in the polycargonate resin (A)' in an amount of 20 to 90% by weight and in the presence of (a) a rubbery polymer. The proportion is between 0 and 20% by weight and 30% of the total monomer mixture.
polymerizing an amount of the monomer mixture corresponding to ~70% by weight;
(b) Then the content of unsaturated nitrile monomer is 35 to 9
The remaining monomer mixture, which is 0% by weight, is polymerized and the above (
a) and (unsaturated di) IJ monomer content in the monomer polymerized portion produced by polymerization of bl to 28 to 38% by weight.
It is characterized by containing 80 to 10% by weight of thermoplastic resin (B).

The polycargonate resin used in the present invention includes commonly used aromatic polycarbonates, aliphatic polycarnates, modified polycarbonates, and the like. Examples of modified polycarbonates include halogenated polycarbonates that have been halogenated with chlorine, bromine, or the like. Among these polycarbonate resins, aromatic polycarbonates are preferred, and aromatic polycarbonates produced by the phosgene method or ester conversion method using bisphenol as the main raw material, particularly those containing 2.2-(4
, 4'-hydroxydiphenyl)-furopane, a so-called 4,4'-dihydroxydiphenyl-based alkane-based polycarzenate obtained using bisphenol Ai, is representative. As these polycarbonate resins, commercially available polycarbonate resins of 9 types can be used as long as their physical properties are clear according to catalog values, etc.

The rubbery polymers used in the present invention include polybutadiene, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer, isofV rubber, chloroprene rubber,
Examples include acrylic rubber and ethylene-propylene-diene rubber, which are produced by conventional emulsion polymerization, solution polymerization, bulk polymerization, and the like.

The monomers used in the production of the rubber-reinforced thermoplastic resin (B) of the present invention are unsaturated nitrile monomers and aromatic vinyl monomers, and examples of the unsaturated nitrile monomers include acrylonitrile, Examples include methacrylonitrile. In addition, aromatic vinyl monomers include styrene, α
- Methylstyrene, p-methylstyrene, O-methylstyrene s m -Methylstyrene, chlorstyrene, bromustyrene, vinylnaphthalene, etc. These monomers may be used alone or in combination of two or more monomers. In addition, if necessary to an extent that affects the purpose of the present invention, other monomers that can be combined, for example, unsaturated acid esters such as methyl methacrylate, may be added to some of the aromatic vinyl monomers. It can be used in place of 6.

The thermoplastic resin (B) of the present invention can be produced, for example, by conventional emulsion polymerization, solution polymerization, or bulk polymerization. That is, a monomer mixture consisting of an unsaturated nitrile monomer and an aromatic vinyl monomer is graft-polymerized in the presence of the rubbery polymer. In the present invention, rubbery polymers 10 to 6
0 part by weight, preferably 20 to 60 parts by weight, of a monomeric polymer consisting of an unsaturated nitrile monomer and an aromatic vinyl monomer, 90 to 40 parts by weight, preferably 80 to 40 parts by weight.
Suitably, 1 part (total of rubbery polymer and monomer mixture is 100 parts by weight) is graft polymerized. If the amount of the rubbery polymer is less than 10 parts by weight, the thermoplastic resin of the present invention has a disadvantage in that the impact resistance is reduced. On the other hand, if it exceeds 601 basins, the amount of graft bonding of the resin component to the rubbery polymer will be small and the thermal stability of the rubber-reinforced thermoplastic resin will decrease, which is not preferable. When blending with polycarbonate resin (4), it is difficult to knead uniformly.

The composition of the monomer mixture of the rubber-reinforced thermoportable resin in the Rei invention is 28 to 38% by weight of unsaturated nitrile monomers and 72 to 62% by weight of aromatic vinyl monomers, preferably 30% by weight of the former. impact resistance of a mixed composition with polycarbonate resin of ~38% by weight, the latter being 70-62% by weight,
In order to improve paint resistance and solvent resistance, unsaturated 2) I
It is preferable that the amount of JL monomer is 28% by weight or more. On the other hand, if the total amount exceeds 38M, disadvantages such as deterioration in processability and impact resistance and a tendency to heat coloring during high-temperature molding become noticeable.

Polycarbonate resin (A) and rubber reinforced thermoplastic resin (
The mixing ratio of B) is 20-90/80-10% by weight, and if the polycarbonate resin is less than 20% by weight, the impact resistance and heat resistance will be low and undesirable, while if it exceeds 90% by weight, the paintability will be improved. is not obtained.

In order to make the present invention more effective, that is, in order to impart special and excellent coating properties and chemical resistance, it is necessary to use monomers in the presence of a monomer in the production of rubber-reinforced thermoplastic resins. Before graft polymerizing the mixture, first step (a)
) in which the content of unsaturated nitrile monomer is O~
20% by weight, preferably from 0 to 18% by weight, and from 30 to 70% by weight of the total monomer mixture, preferably from 30 to 6%.
After polymerizing an amount of the monomer mixture corresponding to 0% by weight,
Then, in the second and subsequent stages of polymerization (b), the content of unsaturated nitrile monomers is preferably 35 to 90% by weight, preferably 40% by weight.
It is important to polymerize the remaining monomer mixture, which is ~70% by weight.

If the content of unsaturated nitrile monomers in the monomer mixture used in the first stage exceeds 20% by weight, chemical resistance will decrease. Furthermore, if the amount of 9 in the monomer mixture used at this stage is less than 30% by weight of the total monomer mixture, the improvement in paintability and chemical resistance is not significant.

On the other hand, if it exceeds 70%, the workability is poor and the effect of improving paintability is small, which is not preferable.

Next, in the second and subsequent stages, the remaining monomer mixture is polymerized, but if the content of unsaturated nitrile monomer in the monomer mixture is less than 35% by weight, paintability and chemical resistance will decrease. death,
On the other hand, if the amount is too large, the polymerization conversion rate decreases, which is not preferable.

Both the first and second stages of the grafting reaction may be carried out by conventional polymerization methods, and monomers, initiators, etc. may be added all at once, in portions, or continuously6.
In addition, the total unsaturated nitrile content in the monomer composition is 28 to 38
In terms of weight %, there is no particular restriction on the distribution of monomers in the case of divided addition.

If the content of the unsaturated nitrile monomer in the monomer polymerized portion of the rubber-reinforced thermoplastic resin thus obtained is 28 to 38% by weight, the mixed composition with the polycarbonate resin will have good chemical resistance and impact resistance. , the physical property balance of workability is good.

Furthermore, at least one kind of aromatic vinyl monomer,
A copolymer of at least one unsaturated IJ monomer and optionally at least one unsaturated acid ester monomer such as methyl dimethacrylate, such as a commercially available As resin, is added to the composition of the invention. Although it is possible to blend the above copolymer and the comb-reinforced thermoplastic resin (Bl), the mixing ratio is preferably 0 to 70/100 to 30% by weight, more preferably 0 to 60/100 to 40% by weight. If (B) is less than 30 inches, the desired effect of the present invention will be reduced.

In these cases, a rubber-reinforced thermoplastic resin containing a large amount of the rubbery polymer of the present invention is prepared in advance, and this is blended with an As resin and a polycarbonate resin to form a final resin composition. 5 to 40% by weight of rubbery polymer
By doing so, good results can be obtained. In addition, in order to improve the chemical resistance, processability, and impact resistance of the final resin composition, the As resin used must have a high content of unsaturated IJ monomers of 30 or more, and 30 The intrinsic viscosity in methyl ethyl ketone at 0.35 ttt is preferably 71 or higher.

The thermoplastic resin composition thus obtained completely improves chemical resistance and paintability, which are disadvantages of polycargonate resins, and has good impact resistance, heat resistance, and processability.

Therefore, its industrial utility value is extremely large in the field of coating materials.

The present invention will be explained in more detail with reference to Examples below; however, the scope of the present invention is not limited by these Examples as long as the scope of the present invention is not exceeded. In addition, in each side below, parts and parts represent ML parts and weight %.

Method for manufacturing rubber-reinforced thermoplastic resin (method for manufacturing rubber-like polymer latex) Using a fatty acid hydroxide as an emulsifier and using a redox initiator consisting essentially of cumene hydroperoxide and ferrous sulfate as an initiator. , t-dotesylmercaptan was used as a chain transfer agent to emulsion polymerize butadiene, and forced stirring was performed during the polymerization to prepare a polybutadiene latex with enlarged latevx particles.

The polymerization time was 60 hours, and the conversion rate was 60%.

The obtained latex A had an average glue content of 78 sb,
The weight fraction of particles of 3100X or more measured by the sodium alginate method was 60%.

Production of rubber-reinforced thermoplastic resin (hereinafter referred to as graft polymer) Reactor vessel equipped with a stirring device, heating jacket, reflux condenser, thermometer, nitrogen gas inlet, and continuous addition device for monomer emulsion and polymerization initiator. The following reagents were charged into the reactor, the reactor was replaced with nitrogen, the temperature was raised, and graft polymerization was carried out at 70° C. for 1 hour.

Rubber-like polymer latex (as solid content) 16 parts Polybutadiene latex (as solid content) 24 parts (JSR0700 manufactured by Japan Synthetic Rubber Co., Ltd.) Styrene 18 parts Acrylonitrile 2 parts Disproportionated potassium rosin acid 1.0 part Terpinolene 0.02 parts Cumene hydroperoxide 0.10 parts Dextrose o, 35 parts Sodium pyrophosphate 0.30 parts Ferrous sulfate o, oi parts Partially ion exchanged water 150 parts Further, the following mixture 't was added continuously over 2 hours. added to.

After adding 22 parts of styrene, 18 parts of acrylonitrile, 0.20 parts of cumene hydroperoxide, and 0.20 parts of terpinolene, the reaction was continued with stirring for an additional hour.

After adding 1.0 part of 2,6-di-t-butyl para-cresol as an anti-aging agent to the obtained ground polymer latex, sulfuric acid (2 parts per 100 parts of polymer) was added,
It solidified. The graft polymer (1) obtained by separating this, washing with water, dehydration, and drying had an acrylonitrile content (according to Coleman analysis, hereinafter the same) of 31% in the monomer polymerized portion. Graft polymer (1) and A obtained in
s resin (acrylonitrile content 32L, intrinsic viscosity 0.45 dl/9 in 30°C methyl ethyl ketone) and polycarbonate resin (Idemitsu Petrochemical Exhibition Polycargone FN2200) were mixed at different composition ratios, and using an extruder. The results of measuring the physical properties of the composition pelletized at 250°C are shown. From this, the thermoplastic resin composition of the present invention has higher impact resistance and better impact resistance than the fcABS resin and polycargonate resin shown in Comparative Example-1. A resin composition with an excellent balance of fluidity, heat resistance, and paintability can be obtained.

Fluidity during processing was measured using a high-performance flow tester (nozzle 1φ
Measurement was performed at 230° C. using a load of 2 m and a load of 3 ok/cm).

The Izotsu impact strength was measured using a 5oz injection molding machine.
A predetermined test piece was molded at 50°C and measured at 23°C according to the method of ASTM D256.

The paintability test was carried out in the following manner by molding test pieces of 55 m x 80 parts m x 1.6+ m at 250° C. using a 1-ounce injection molding machine. Urethane paint (granet) on the test piece
PA Origin Electric Co., Ltd.) was spray painted, and after drying, it was left to stand for a certain period of time (3:1).It was immersed in L gasoline, and the time until the urethane coating swelled and peeled was measured. It is determined that the longer this time is, the better the coating performance is.

Example-2, Comparative Example-2 Styrene and acrylonitrile during graft polymerization are shown in Table-2
Polymerization and blending were carried out in the same manner as in Example 1 except for the following changes. Table 2 shows the composition of the graft polymer and the physical properties of the obtained resin.

Comparative Example-3 Complete table of styrene and acrylonitrile during graft polymerization-2
Polymerization and blending were carried out in the same manner as in Example 1, except for using the excess amount shown in . Composition of graft polymer and graft polymer, AS resin, d? The physical properties of the resin, which is a mixture composition of IJ carbonate resin, are also listed in Table 2.

From the results shown in Table 2, Comparative Example 3 (1) has a low acrylonitrile content in the graft polymer composition, so the coating performance of the final composition is poor. (2nd is acryloni on the contrary) I
Since the JL content is too high, the fluidity of the final composition is poor and the surface condition of the coated product cannot be obtained.

Example-3, Comparative Example-4 The following reagents were charged to the reaction amount described in Example-1,
The mixture was replaced with nitrogen, the temperature was raised, and graft polymerization was carried out at 70° C. for 1 hour.

Rubber polymer (as solid content) 9.6 parts (same as Example-1) Polybutadiene latex (as solid content) 14.4
Part (JSR0700 manufactured by Japan Synthetic Rubber Co., Ltd.) Styrene
22 parts acrylonitrile 4 parts disproportionated potassium rosinate 1.5 parts t-dodecyl mercaptan 0.03 parts cumene hydroperoxide 0.10 parts Dextrose 0.35 parts Sodium birophosphate 0.30 parts Ferrous sulfate 0, 01 parts ion-exchanged water 150 parts K1 The following mixture was added continuously over 2 hours.

After adding 28 parts of styrene, 22 parts of acrylonitrile, 0.18 parts of cumene hydroperoxide, and 0.25 parts of t-dodecylmercaptan, the reaction was continued with stirring for an additional hour. After adding 1.0 part of 2,6-di-t-butylno or Raffresol as an anti-aging agent to the obtained graft polymer latex, a graft polymer was obtained by the method described in Example-1. The acrylonitrile content of this monomer polymerized portion was 31%.

Next, 50 parts by weight of the obtained graft polymer and 50 parts by weight of polycarbonate resin were mixed, pelletized and each test piece was prepared in the same manner as in Example-1, and the measurement results are shown in Table 1.
Shown in 3. Similar results were obtained by changing the monomer composition ratio at the time of graft polymerization in the above examples, and the same results were shown in Cloth-3 as Examples and Comparative Examples.

When the acrylonitrile content in the styrene-acrylonitrile composition in the graft polymer is within the range of the present invention, the coating appearance is excellent, and in particular, in the production method during graft polymerization, the acrylonitrile content in the early stage of polymerization is It is clear that the coating shown in this example, which contains 20% by weight, has excellent swelling and peeling properties.

Comparative Example-5 In the polymerization recipe of Example-3, polymerization components other than styrene, acrylonitrile, and cumene hydroperoxide were charged into a reactor, and the temperature was raised while purging with nitrogen. The ftk was added continuously for the entire 3 hours. The polymer was recovered and evaluated in the same manner as in Example 3, and the results are shown in Cloth 3.

Claims (1)

[Claims] (1) In the presence of polycarbonate resin (A) t-20 to 90% by weight and (,) a rubbery polymer, first, the content of unsaturated nitrile monomer is 0 to 20% by weight. (b) polymerizing the monomer mixture in an amount corresponding to 30 to 70% by weight of the total monomer mixture;
The remaining monomer mixture, which is 90% by weight, is polymerized, and the content of unsaturated nitrile monomer in the monomer polymerization portion produced by the polymerization of (aj and (b)) is t-28 to 38% by weight. % thermoplastic resin (B) in an amount of 80 to 10% by weight.