JPH04252216A - Graft copolymer having processability-improving effect and thermoplastic resin composition compounded therewith - Google Patents

Abstract

PURPOSE:To provide a graft copolymer for compounding to a thermoplastic resin to improve the moldability of the resin. CONSTITUTION:The objective graft copolymer having a reduced viscosity (etasp/c) of >=2 (isolated polymer) and effective for improving the moldability of a resin can be produced by the graft-polymerization of (A) 80-10 pts.wt. of one or more monomers selected from a styrene monomer, a methacrylic acid ester and an acrylic acid ester in the presence of (B) 20-90 pts.wt. (in terms of solid) of a rubber (a) latex of a non-crosslinked ethylene-propylene-nonconjugated diene copolymer. A thermoplastic resin composition having good moldability is produced by compounding 0.01-20 pts.wt. of the graft copolymer to 100 pts.wt. of a thermoplastic resin.

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graft copolymer having properties that improve the processability of thermoplastic resin compositions, such as promoting melting and preventing drawdown during processing. Furthermore, the present invention provides the graft copolymer with vinyl chloride resin, polycarbonate resin, polyester resin, A
The present invention relates to a thermoplastic resin composition with good processability, which is blended with a thermoplastic resin such as BS resin, styrene resin, methacrylic resin, or polyethylene resin.

2. Description of the Related Art Thermoplastic resins, particularly vinyl chloride resins, are widely used in various fields because of their excellent physical and chemical properties. However, vinyl chloride resin has the disadvantage of poor processability in various ways, and as a solution to this problem, plasticizers, copolymer processing aids mainly composed of methyl methacrylate, and lubricants are added and blended. This has been attempted, but it has not been a general solution. Therefore, in order to solve these problems, we have improved processability such as promoting melting during molding and preventing drawdown.
Furthermore, various developments are being carried out with the aim of improving the gloss and smoothness of molded products; for example, Japanese Patent Publication No. 52-781
Publication No. 52-3668, Special Publication No. 53-2
Vinyl chloride resin compositions disclosed in Japanese Patent No. 898 and the like have been proposed.

[Problems to be Solved by the Invention] However, especially with vinyl chloride resin, the processing temperature during processing is close to the thermal decomposition temperature, so the molding area is narrow and the molding process is extremely poor, resulting in improved productivity and quality. Expected physical properties cannot be obtained unless a special processing machine or special technology is used in order to improve the performance and save energy. The vinyl chloride resin compositions proposed in the above-mentioned publications have limitations and cannot be said to fully satisfy market demands. The purpose of the present invention is to provide a processing aid that can be blended into a thermoplastic resin to sufficiently improve its processability, as well as a thermoplastic resin compound that is blended with the processing aid and has excellent processability. shall be.

[Means for Solving the Problems] As a result of intensive studies to obtain a processing aid that satisfies the above objectives and has the effect of improving processability, the present inventors have developed a non-crosslinked ethylene-propylene-nonconjugated diene copolymer. A graft copolymer obtained by polymerizing rubber with at least one monomer selected from the group consisting of a styrene monomer, a methacrylic acid ester, and an alluric acid ester, and which is extracted with acetone. A graft copolymer whose free polymer has a reduced viscosity ηsp/c in a specific range has an excellent processability improvement effect, and by blending a specific amount of this graft copolymer with another thermoplastic resin, It was discovered that a thermoplastic resin composition with excellent processability can be obtained, and the present invention was achieved. That is, the present invention provides 80 to 10 parts by weight of the styrene monomer methacrylate in the presence of 20 to 90 parts by weight (as solid content) of a non-crosslinked ethylene-propylene-nonconjugated diene copolymer rubber (a) latex. At least one monomer (b) selected from the group consisting of acid esters and acrylic esters
Graft copolymerization obtained by polymerizing [total amount of (a) + (b) 100 parts by weight], the reduced viscosity ηsp/c of the free polymer when extracted with acetone is 2 or more (polymer 0
．． 1g dissolved in 100ml of chloroform and measured at 25°C) is a graft copolymer that has a processability improving effect. The present invention relates to a thermoplastic resin composition containing 0.01 to 20 parts by weight of a graft copolymer having the following properties. The ethylene-propylene-nonconjugated diene copolymer non-crosslinked rubber used in the present invention includes ethylene, propylene, and a third component such as dicyclopentadiene.
ethylidene norbornene, 1,4-hexadiene, 1,
5-hexadiene, 2-methyl-1,5 hexadiene,
Ethylene consisting of one or more non-conjugated dienes such as 1,4-cycloheptadiene and 1,5-cyclooctadiene
Propylene non-conjugated dienter polymer (EPDM)
). As the non-conjugated diene component in EPDM, it is particularly preferable to use one or more of dicyclopentadiene and ethylidene norbornene. EPD
The molar ratio of ethylene and propylene in M is 5:1 to 1
:3, and the proportion of unsaturated groups in EPDM is preferably in the range of 4 to 50 in terms of iodine value. There are no particular restrictions on the method for producing EPDM latex, but it is common to apply mechanical shearing force to EPDM in the presence of an emulsifier to stabilize fine dispersion in water to form a latex. The particle size of the EPDM latex is preferably 2 μm or less. If a material with a diameter exceeding 2 μm is used, when the graft copolymer obtained by graft polymerization is blended with other thermoplastic resins and molded, it will affect the transparency and gloss of the molded product, resulting in poor quality. A molded product cannot be obtained. The EPDM used in the present invention needs to be non-crosslinked. If this EPDM is crosslinked, the moldability during molding will be poor, and the effect of improving processability will not be obtained, which is not preferable. Further, in the present invention, the content of the non-crosslinked ethylene-propylene-nonconjugated diene copolymer rubber (a) in the graft copolymer is preferably 20 to 90 parts by weight (as solid content), preferably 30 to 80 parts by weight. be. Content is 2
If the content is less than 0 parts by weight, the processability improvement effect that is the objective of the present invention cannot be obtained, and if the content exceeds 90 parts by weight,
The surface gloss of the molded product after molding tends to be poor. The graft copolymer in the present invention is produced by an emulsion polymerization method. The production of the graft copolymer of the present invention involves EPD
In the presence of 20 to 90 parts by weight (as solid content) of latex M(a), at least one monomer selected from the group consisting of styrene monomers, methacrylic esters, and acrylic esters (b ) 80 to 10 parts by weight [(a)+
100 parts by weight of monomer (b)] in the presence of a radical polymerization initiator, the entire amount of monomer (b) is added all at once, in portions, or continuously to latex and polymerized. . Examples of polymerization initiators include thermal decomposition type initiators such as potassium persulfate and ammonium persulfate, or sugar-containing pyrophosphate formulations that are a combination of cumene hydroperoxide, iron compound, sodium pyrophosphate, and dextrose. Redox initiators can be used. Tert-butyl hydroperoxide, diisopropylbenzene hydroperoxide instead of cumene hydroperoxide
Oxide etc. can also be used. Ethylenediaminetetraacetic acid sodium salt (EDTA) is used instead of sodium pyrophosphate.
-2Na) can also be used. It is also possible to use sodium formaldehyde sulfoxylate instead of dextrose. During graft polymerization, it is preferable to add an additional emulsifier to stabilize the polymerization. As the emulsifier, any anionic emulsifier that can be used in normal emulsion polymerization can be used without any particular restriction, but fatty acid soaps, rosin acid soaps, etc. are common. The monomer (b) used in the production of the graft copolymer of the present invention has the effect of improving the processability of the polymer, that is, preventing drawdown during molding, accelerating the melting rate, and producing large molded products. In order to make it possible to mold, methacrylic esters and acrylic esters, which have good compatibility with vinyl chloride resin, and styrene, α-methylstyrene, etc., which have poor compatibility with vinyl chloride resin, are used. By increasing the melt viscosity, the above-mentioned processability improvement effect can be exhibited. Reduced viscosity ηsp
/c may be in the range of 2 or more, preferably 15 or less. If it is 15 or more, it is not preferable because when blended with vinyl chloride resin, good dispersibility will not be exhibited and the processability improvement effect will not be improved. The reduced viscosity can be adjusted as appropriate by adjusting the chain transfer agent, catalyst, and polymerization temperature used during polymerization. Further, the reduced viscosity ηsp/c defined in the present invention is measured by dissolving 0.1 g of the above graft copolymer in 100 ml of chloroform and using an Ostwald viscometer at 25°C. The above graft polymer resin may be a vinyl chloride resin, a polycarbonate resin, a polyester resin, or
By blending 0.01 to 20 parts by weight per 100 parts by weight of a thermoplastic resin such as BS resin, methacrylic resin, or polyethylene resin, it gives the thermoplastic resin the effect of improving processability, that is, it reduces drawdown during molding. It is possible to make a resin composition that can prevent the above-mentioned problems and enable the molding of large-sized products, and can also be used to mold molded products with excellent shape, gloss, and smoothness. If the blending amount of the graft polymer resin exceeds 20 parts by weight, the melt viscosity of the resin will be too high during molding.
This is undesirable because the amount of heat generated increases and discoloration of the molded product occurs. The graft copolymer resin of the present invention may be added to a thermoplastic resin by mixing according to a conventional method. In addition, this resin composition may contain stabilizers such as organotin compounds, lead-based, barium-based, zinc-based metal soaps, and other epoxy compounds; stearic acid, ester wax, paraffin wax, and stearyl. , lubricants such as alcohol; plasticizers such as phthalate esters, phosphate esters, fatty acid esters, and epoxy systems; colorants such as carbon black and titanium oxide; fillers such as calcium carbonate and asbestos; Inorganic foaming agents such as ammonia carbonate and sodium bicarbonate; organic foaming agents such as nitro, sulfohydrazide and azo foams may also be blended.

[Examples] The present invention will be explained in further detail with reference to Examples and Comparative Examples below. Note that all "parts" in Examples and Comparative Examples indicate parts by weight. In addition, the reduced viscosity ηsp/c of each polymer is
Reduced viscosity η sp / of the free polymer obtained by extracting the graft polymer resin obtained by polymerization with acetone using specified emulsifier, polymerization initiator, polymerization temperature, and chain transfer agent as variables.
c was measured and set as ηsp/c. Example 1 EPDM was added to a reaction vessel equipped with a stirrer and a reflux condenser.
Latex (average particle size 0.1 μm) 60 parts (as solid content), potassium oleate 1.0 part, cumene hydroperoxide 0.2 part, methyl methacrylate 40 parts,
After charging 0.01 part of n-octyl mercaptan and purging the inside of the container with nitrogen, 0.2 part of sodium formaldehyde sulfoxylate was added under stirring. The temperature of the reaction container was raised to 70°C. The mixture was heated and stirred for an hour to complete the polymerization. After cooling the obtained polymer latex, sulfuric acid was added thereto, the mixture was coagulated, filtered and washed, and dried to obtain a polymer powder. Examples 2 to 8 and Comparative Examples 1 to 2 The graft polymer (powder polymer) obtained in Example 1 was
100 parts of polyvinyl chloride resin (average degree of polymerization 700),
1.5 parts of butyltin mercapto, 1.0 part of epoxy auxiliary agent, and 0.3 part of lubricant were added in the proportions shown in Table 1, and mixed in a Henschel mixer to obtain a vinyl chloride resin composition. The following evaluation was performed using this composition. The results are shown in Table 1. The evaluation conditions are as follows. Extrusion moldability: 25φm/m Using a single-screw extruder, extrude with a nozzle diameter of 0.5mmφ and extrusion rotation speed of 50 rpm, cut the strand extruded from the nozzle in 20 seconds, and measure its length and diameter (width). It was measured. The shorter the length, the smaller the drawdown property, and the wider the width, the better the die swell behavior and the better the secondary processability. Extrusion conditions: C1 = 160°C C2 = 170°C C3
= 180°C D = 180°C Number of revolutions = 50 rpm Breaking elongation: A sheet of 2 mm thickness was obtained by pressing a sheet using a 6-inch roll at a pressing temperature of 180°C for 7 minutes. A D-type dumbbell piece (ISO No. 3 type) was made from the sheet, and a tensile tester was used to test it at 50 mm/min in an atmosphere of 120°C.
The tensile test was conducted at a speed of . The larger the elongation at break, the better the secondary workability. Appearance: The condition of the strand extruded by the extruder (surface characteristics, smoothness, gloss) was visually judged. The results are indicated by ◎ being the best and ◎~〇, 〇, △, and ×.

[Table 1] Examples 9 to 15 and Comparative Examples 3 to 4 Polymerization was carried out under the same conditions as in Example 1 and with the compositions shown in Table 2 to obtain various powder polymers. 3 parts of these various polymers were mixed with 100 parts of polyvinyl chloride resin (average degree of polymerization 700), 1.5 parts of butyl mercapto, 1.0 part of epoxy auxiliary agent, and 0.3 part of lubricant in a Henschel mixer. A vinyl chloride resin composition was obtained. Using this composition, extrusion moldability (under the above conditions), elongation at break (under the above conditions), and appearance (under the above conditions) were evaluated. The results are shown in Table 2. In addition, in Comparative Example 3, the material was blocked during aggregation and could not be powdered.

[Table 2] Examples 16 to 22 and Comparative Examples 5 to 11 100 parts of each of the following thermoplastic resins were blended with 3 parts of the polymer obtained in Example 1, and 3 parts of the polymer obtained in Example 1 were blended, and 100 parts of each of the following thermoplastic resins were mixed in a Henschel mixer. mixed with. Using a single screw extruder (25φm/m), the resulting mixture was tested for extrusion moldability by measuring the amount of extrusion (g/10 min) for each resin at different temperatures as shown below. Moreover, the pressure (Kg-m) during extrusion was measured. The larger the extrusion amount and the lower the pressure, the greater the slipperiness. (1) ABS resin (Diapet ABS#3001; trade name, manufactured by Mitsubishi Rayon Co., Ltd.) Molding temperature: C1 = 180°C, C2 = 200°C, C3 = 2
00℃, head = 200℃, die = 200℃ (2) Styrene resin (Styrene NF-20; trade name,
(manufactured by Idemitsu Petrochemical Co., Ltd.) Molding temperature: C1 = 160°C, C2 = 180°C, C3 = 2
00°C, head = 200°C, die = 210°C (3) Polycarbonate resin (Novarex 7022:
Product name, manufactured by Mitsubishi Chemical Industries, Ltd.) Molding temperature: C1 = 230°C, C2 = 260°C, C3 = 2
70°C, head = 270°C, die = 280°C (4) Polyethylene resin (Hyzex 7000F; trade name, manufactured by Mitsui Petrochemical Industries, Ltd.) Molding temperature: C1 = 150°C, C2 = 165°C, C3 = 1
75°C, head = 175°C, die = 175°C (5) Polyester resin (Dianite PA-200:
Product name, manufactured by Mitsubishi Rayon Co., Ltd.) Molding temperature: C1 = 280°C, C2 = 280°C, C3 = 2
80°C, head = 260°C, die = 260°C (6) Polyphenylene ether resin: PPE (Noryl
731J GE Plastics Co., Ltd.) Molding temperature: C1 = 200°C, C2 = 260°C, C3 = 2
60℃, head = 260℃, die = 260℃ (7) Vinyl chloride resin (Zeon PVC polymerization degree 700
) Molding temperature: C1=160°C, C2=170°C, C3=
180℃, head = 175℃, die = 180℃

[Table 3]

[Effect of the invention] As is clear from Tables 1 to 3 above,
By blending the graft polymer of the present invention with various thermoplastic resins, extrusion moldability during molding of various thermoplastic resins,
The high-temperature elongation of the molded product can be improved, and the appearance (surface characteristics, bumps, smoothness, gloss), etc. of the molded product are good. Furthermore, when the graft polymer of the present invention is blended with various thermoplastic resins, it has the effect of improving processability such as promoting melting and preventing drawdown during forming processing, making it possible to mold large-sized molded products. Moreover, it has the effect of improving productivity.

Claims (2)

[Claims] Claim 1: 20 to 90 parts by weight of non-crosslinked ethylene-propylene-nonconjugated diene copolymer rubber (a) latex (
80 to 10 parts by weight of at least one monomer selected from the group consisting of styrenic monomers, methacrylic esters, and acrylic esters (as solid content).
b) A graft copolymer obtained by polymerizing [total amount of (a) + (b) 100 parts by weight], which has a reduced viscosity ηsp/c of 2 or more (polymer) when extracted with acetone. Dissolve 0.1 g of the combined substance in 100 ml of chloroform,
A graft copolymer having an effect of improving processability (measured at 5°C). [Claim 2] 0.01 parts by weight of the graft copolymer having the processability improving effect according to Claim 1 per 100 parts by weight of the thermoplastic resin.
A thermoplastic resin composition containing ~20 parts by weight.