JPS6069153A - Thermoplastic resin composition having excellent resistance to heat and impact - Google Patents

Abstract

PURPOSE:To provide the titled thermoplastic resin compsn. having good flow processability, consisting of a specified copolymer and an acrylate ester graft copolymer. CONSTITUTION:The titled compsn. consists of 1-99% copolymer (A) composed of 50-98% methyl methacrylate, 1-25% alpha-methylstyrene and 1-25% maleic anhydride and 1-99% acrylate ester graft copolymer (B) obtd. by polymerizing 10-1,000pts. monomer (mixture) consisting of 100-60% monomer selected from among methyl methacrylate and styrene and 0-40% other vinyl monomer in the presence of 100pts. crosslinked acrylate ester copolymer obtd. by polymerizing a monomer mixture consisting of 50-99.9% 1-8C alkyl acrylate, 0-40% other vinyl monomer and 0.1-10% crosslinking monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic resin with excellent heat resistance and impact resistance, and more specifically, the present invention relates to a thermoplastic resin having excellent heat resistance and impact resistance. The present invention relates to a thermoplastic resin composition having excellent heat resistance and impact resistance and comprising an acrylic acid ester graft copolymer and an acrylic acid ester graft copolymer.

Until now, as a method to obtain thermoplastic resins with excellent heat resistance and impact resistance, graft copolymers, which are made by graft copolymerizing styrene or acrylonitrile to diene rubber, have been used.
A method of mixing a terpolymer consisting of α-methylstyrene, methyl methacrylate, and acrylonitrile (Japanese Patent Publication No. 57-70143) or a method of mixing a polycarbonate resin and a diene rubber (Japanese Patent Publication No. 38-198)
No. 5225) and the like have been proposed. However, these methods have problems such as difficulty in achieving a balance between heat resistance and impact resistance, and in the case of mixtures of polycarbonate and diene rubber, flow processability is significantly reduced.
The reality is that a material that has both heat resistance and impact resistance has not yet been developed.

The inventors have developed a material with good heat resistance and flow processability.

As a result of intensive studies on impact-resistant thermoplastic resin compositions, it was discovered that a resin composition of a polymer having a specific composition and structure satisfactorily achieves the intended purpose, and the present invention was achieved.

The gist of the present invention is that methyl methacrylate 50
A copolymer obtained by polymerizing a monomer mixture consisting of ~98% by weight, 1-25% by weight of α-methylstyrene, and 1-25% by weight of maleic anhydride [with 131-99% by weight].

(a) 50 to 99.9 weight ts of an acrylic acid alkyl ester with an alkyl group having 1 to 8 carbon atoms, 0 to 40 weight % of other copolymerizable vinyl monomers, and copolymerizable crosslinking monomers Crosslinked acrylic acid ester copolymer 100 obtained by polymerizing a monomer mixture consisting of 0.1 to 10% by weight
In the presence of weight parts.

(b) A monomer consisting of 60 to 100% by weight of at least one monomer selected from methyl methacrylate or styrene, and 0 to 40% by weight of another vinyl monomer copolymerizable with this monomer. or 10 to 1,000 parts by weight of a mixture thereof to obtain a thermoplastic resin composition with excellent heat resistance and impact resistance consisting of 1 to 99% by weight of an acrylic ester-based graft copolymer (n) obtained by K. be.

The composition of the present invention is characterized by the above-mentioned methyl methacrylate, α
- Copolymer of methylstyrene and maleic anhydride (1
The synergistic effect of 1 and the acrylic acid ester graft copolymer (If) component makes it possible to exhibit excellent, well-balanced properties in heat resistance, impact resistance, and flow processability.

The crosslinked acrylic ester copolymer [I] in the present invention has a weight ratio of 50 to 98 methyl methacrylate.

It is a polymerized monomer mixture consisting of 1 to 25% by weight of α-methylstyrene and 1 to 25% by weight of maleic anhydride, and has the effect of imparting heat resistance and flow processability to the final resin composition. have. In addition, the proportions of the constituent units of methyl methacrylate, α-methylstyrene, and maleic anhydride in the copolymer [■] are determined to balance the heat resistance, weather resistance, polymerization rate, flow processability, etc. of the copolymer [I]. (5), and if any monomer component is outside the above range, problems such as poor heat resistance and weather resistance and extremely poor productivity will occur. The proportion of the copolymer (1) in the total resin composition is 1 to 99% by weight, more preferably 10 to 90% by weight. If it is less than 1% by weight, heat resistance and flow processability will be poor; If it exceeds this, impact resistance tends to be poor.

Copolymer [I] can be produced by a commonly used polymerization method such as bulk polymerization or solution polymerization of the above monomer mixture using a radical polymerization initiator. If necessary, it is also possible to add other copolymerizable monomer units having a weight ratio of 10 or less as a fourth component.

The acrylic acid ester-based graft copolymer (1) has the effect of imparting impact resistance to the target resin composition, and is suitably contained in an amount of 1 to 99% by weight in the entire resin composition. More preferably 10 to 900 to 90% by weight.If it is less than 1% by weight, the impact resistance will be poor, and if it exceeds 99% by weight, the heat resistance will be poor, and both (6) are not preferred.

When dispersing the acrylic ester-based graft copolymer [1] used in the present invention in a resin composition, in order to achieve a good balance between appearance characteristics and impact resistance, the acrylic ester-based graft copolymer [■] It is necessary to limit the particle size2, usually 0.05 to 0.5 μm, more preferably 0.
．． It is necessary to set it in the range of 0.08 to 0.2 μm.

The acrylic acid ester graft copolymer [11] is produced in two steps. The first step (a) is.

Acrylic acid alkyl ester with an alkyl group having 1 to 8 carbon atoms, 50 to 99,9 weight percent, other vinyl monomer copolymerizable with this, 0 to 40 weight percent, and 2 carbon atoms in the molecule.
It is a copolymerized monomer mixture consisting of 0.1 to 10 weight percent crosslinkable monomers having two or more double bonds, and examples of the acrylic acid alkyl ester include butyl acrylate, acrylic acid-2- Ethylhexyl and the like are preferred. Other vinyl monomers that can be copolymerized with this include aromatic vinyl monomers represented by styrene, acrylonitrile, methyl methacrylate, butyl methacrylate, acrylic acid, methacrylic acid, maleic acid, etc. . Examples of the copolymerizable crosslinking monomer include ethylene glycol dimethacrylate, 1,3-butylene dimethacrylate, ethylene glycol diacrylate, and trimethylolpropane triacrylate.

Allyl methacrylate, allyl cinnamate.

Divinylbenzene, triallyl cyanurate.

Examples include triallyl in cyanurate, allyl rubate, diallyl phthalate, diallyl maleate, etc.
Preferred are 1,3-butylene dimethacrylate, divinylbenzene, allyl acrylate, triallyl isocyanurate, and allyl cinnamate, which may be used alone or in combination.

In the second step (b), in the presence of the crosslinked acrylic ester copolymer obtained in the first step, 60% by weight or more of methyl methacrylate, styrene, or methyl methacrylate and methyl ref.

It is obtained by polymerizing a monomer mixture consisting of 40 weight percent or less of other copolymerizable vinyl monomers, and the copolymerizable vinyl monomers include aromatic vinyl other than styrene, Examples include ethyl methacrylate, acrylonitrile, methacrylic acid, acrylic acid, ethylene glycol dimethacrylate, and acrylic acid alkyl esters in which the alkyl group has 1 to 8 carbon atoms. More preferred are acrylonitrile, acrylic acid alkyl esters having 1 to 8 carbon atoms, acrylic acid, methacrylic acid, ethylene glycol diacrylate, and the like. However, when using crosslinkable monomers among these monomers, care should be taken in the amount added and in the polymerization operation. For example, in the polymerization operation, a predominant amount of methyl methacrylate or styrene/ It is also possible to divide the monomer or a mixture thereof into a portion to which the crosslinkable monomer is added and a portion to which it is not added, and polymerize them individually.

Each stage constituting the acrylic acid ester graft copolymer [111, that is, the first stage (a) and (9) and the second stage (b), does not need to have a homogeneous composition (as disclosed in the patent) It is also possible to vary the composition within the scope of the claims.

In the acrylic ester-based graft copolymer [■], the second stage (b) is polymerized in the presence of 100 parts by weight in the first stage (a), 10 to 1000 parts by weight in the second stage,
Preferably, it is 20 to 500 parts by weight.

Outside these ranges, problems arise such as an imbalance between impact resistance and appearance, low impact resistance, and poor productivity.

In addition, for the monomers constituting the first stage in (a) and the second stage in (b), a degree of polymerization regulator such as mercaptan can be used to adjust the molecular weight as necessary. It is. Examples of polymerization degree regulators that can be used include alkyl mercaptans, thioglycolic acid and its esters, β-mercaptopropionic acid and its esters, and thiophenol.

Examples include aromatic mercaptans such as thiocresol.

The resin (10) with excellent heat resistance and impact resistance of the present invention In order to produce the resin composition, it is particularly preferable to use the emulsion polymerization method for the acrylic ester graft copolymer [n]. This will be explained using an example of the polymerization method.

After adding deionized water, a polymerization initiator, and an emulsifier to the reaction vessel, the monomer mixture constituting the first step of (a) was polymerized.
Then, the monomer mixture constituting the second stage of (bl) is polymerized. The polymerization temperature is 30 to 120 °C, more preferably 5
The temperature is 0 to 100°C.

The polymerization time varies depending on the type and amount of the polymerization initiator and emulsifier, the degree of polymerization, etc., but is usually 0.5 to 7 hours for each polymerization stage (al and bJ).

The ratio of polymer to water is preferably monomer/water=]/20 to 1/1.

The polymerization initiator and emulsifier can be added to either or both of the aqueous phase and the monomer phase.

The method of charging each monomer in the polymerization steps (at and (bl) can be carried out all at once or in portions, but the split charging method is more preferable from the viewpoint of polymerization heat generation and the like.

Emulsifiers do not need to be particularly limited as long as they are commonly used, but examples include long chain alkyl carbo/acid salts,
These include sulfosuccinic acid alkyl ester salts and alkylbenzene sulfonate salts.

There is no need to particularly limit the type of polymerization initiator, and commonly used inorganic initiators such as persulfates and perborates can be used alone or in combination with sulfites and thiosulfates as redox initiators. In addition, redox initiation systems such as organic hydroperoxides - ferrous and ihydroperoxide di formaldehyde sulfoxylates - initiation systems such as benzoyl peroxide and azobisin butyronitrile can also be used.

The polymer latex obtained by the emulsion polymerization method is coagulated and dried by a known method.

The composition of the present invention is composed of a copolymer CI) and an acrylic acid ester graft copolymer [U],
Other methacrylic resins, polycarbonate, and AS resins depending on the purpose of use.

Methyl methacrylate-styrene copolymer, Boristyrene/
At least one resin (1) selected from polyester, polyester (polyethylene terephthalate, polybutylene terephthalate), and nylon may be added to the composition in an amount of 98% by weight or less. For example, when extremely good weather resistance is required, methacrylic resins and polyethylene terephthalate resins are suitable, and when high fluidity is required, Boristyrene, A8 resin 8, and methyl methacrylate-styrene resins are suitable. Polymers are used.

In addition, in the composition of the present invention, stabilizers, lubricants, plasticizers, dyes and pigments, fillers, etc. may be added as appropriate.
After mixing with a V-type blender, Henschel ξ mixer, etc., use a mixing roll, screw extruder, etc.
Melt mix at 50-300°C.

By molding the obtained composition using an extrusion molding machine, an injection molding machine, etc. (13), molded products with excellent heat resistance and impact resistance can be obtained, so they can be used for vehicle exterior parts, Nura system equipment, etc. It is useful for applications such as parts and electrical parts.

In the following examples, the weight means % by weight.

Examples 1-4. Comparative Examples 1 to 3 Production of Copolymer (1) Methyl methacrylate (66k) was placed in a SUS reaction vessel equipped with a cooling tube, a thermometer, and a stirring device.

α-methylstyrene 19ky, maleic anhydride 15kg
, i-dodecyl mercaptan 2507' was charged, and nitrogen gas was blown into the system while stirring to expel air from the system. After that, it was heated, and at an internal temperature of 7°C, 200P of 2.2'-azobis+2.4-dimethylvaleronitrile was added, and the internal temperature was maintained at 95°C for 15 minutes, and then cooled to room temperature to form a viscous partial polymer. I got it.

For 100 k) of this partial polymer, lauroyl peroxide 400F, t-dodecyl mercaptan 300
P+ Tinuvin -P (manufactured by Ciba Geigi (14)) 30F, JP-504 (manufactured by Sanka Kagaku Co., Ltd.) 20
JP, Mark-329 (Adeca Argus Co., Ltd.)
) 100J', stearic acid monoglyceride 100
After adding P and stirring thoroughly to dissolve it, it was first poured into several sets of cells made of two tempered glass plates facing each other at a distance of 6 mm with a polyvinyl chloride gasket interposed therebetween, and thermocouples were set. A partially polymerized product adjusted to 100% was injected into the container and immersed in warm water at 80° C. to polymerize and harden. After confirming that the internal temperature of the cell reached a peak after immersion, polymerization was continued for an additional 30 minutes, and then the cell was taken out of the warm water and heat-treated in an air heating oven at 130° C. for 2 hours. After cooling, the cell was removed to obtain a resin plate with a thickness of about 6 mm. This plate-like polymer was cut and crushed into pellets.

Production of acrylic acid ester-based graft copolymer (II) (a) First step Deionized water (hereinafter abbreviated as DW) 3zky, Nonsal T
K-1 (manufactured by NOF Corporation, hereinafter abbreviated as TK-1) 20
0F, ferrous sulfate 0.01! , ethylenediaminetetraacetic acid disodium (hereinafter abbreviated as EDTA-2Nm) 0.5
7', sodium formaldehyde sulboximinate (
(hereinafter abbreviated as 5F8) s containing 25t.

l Butyl acrylate 98.7% in a SUS reaction vessel
, allyl methacrylate 1.0%, tert-butyl hydroperoxide (hereinafter abbreviated as t-BE) 0.3%
After charging 3 kg of the mixture and replacing the oxygen in the reaction vessel with nitrogen, polymerization was carried out at 70'C for 2 hours with stirring.

1 kg of a 5% aqueous solution of TK-1 was added. Thereafter, 7 kg of a mixture having the same composition as that previously polymerized was added continuously over 2 hours, and after the addition was completed, polymerization was continued for another 2 hours.

(b) Second stage To the same reaction vessel where the first stage was completed, 1 kg of 5% TK-1 aqueous solution was added, and the same 70% as in the first stage was added. Under the conditions of
Methyl methacrylate 96.7%, methyl acrylate 3%
, n-Dm (hereinafter abbreviated as n-Dm), 0.3 t-BHo, 2% mixture was continuously added over 90 minutes, and after the addition was completed, polymerization was continued for an additional hour.

The latex particle diameter calculated by absorbance method is 0.12μ
It was m.

The latex of the obtained graft copolymer (U) was 0.2
It was coagulated with 5% sulfuric acid water at latex/water = 172.50°C. The obtained slurry-like white polymer was
It was washed with 0x DW, dehydrated, and then dried at 75° C. for 36 hours.

Next, the copolymer (1) obtained above, the acrylic ester graft copolymer (II), and the other resin (1) were mixed in a Henschel mixer in the proportions shown in Table 1, and then mixed in a screw extruder. Using cylinder temperature 200~27
0℃.

The mixture was melt-kneaded at a die temperature of 260°C and pelletized. This was injection molded under the following conditions, and the evaluation results shown in Table 1 were obtained from the obtained test pieces.

(17) Injection molding machine: V-17-65 screw set automatic injection molding machine manufactured by Japan Steel Works. Injection molding conditions: Cylinder temperature change Injection pressure 700 kg/cm" Mold temperature 52°C Test piece size: 110X110X2 ( Thickness) Dragon 70
X 12.5
The amount of monomer mixture 4 used during one-step production was reduced from 30 to 1
．． All of the samples were manufactured in the same manner as in Examples 1 to 4 except that the sample was changed to 50%. Using the same, blends were formed in the proportions shown in Table 1.

The obtained pellets were evaluated in the same manner as in Examples 1 to 4, and the results shown in Table 1 were obtained. (18) Examples 7 to 11. Comparative Examples 4 to 5 The proportions of copolymer [1] and acrylic acid ester graft copolymer [...] used in Examples 1 to 4, and the type and proportion of resin [1] were as shown in Table 2. Example 1~
Evaluation was performed in the same manner as in 4, and the results shown in Table 2 were obtained.

Claims (1)

[Claims] 1. 50-98% by weight of methyl methacrylate, 1-25% by weight of α-methylstyrene, and 1-2% by weight of maleic anhydride.
A copolymer obtained by polymerizing a monomer mixture consisting of 5% by weight [111 to 99% by weight]. (a) Acrylic acid alkyl ester in which the alkyl group has 1 to 8 carbon atoms 50 to 99.9X1%. Crosslinked acrylic ester obtained by polymerizing a monomer mixture consisting of 0 to 40% by weight of another copolymerizable vinyl monomer and 0.1 to 10% by weight of a copolymerizable crosslinkable monomer. In the presence of 100 parts by weight of the copolymer. (b) A monomer consisting of 60 to 100% by weight of a monomer selected from methyl methacrylate or styrene, and 0 to 40% by weight of another vinyl monomer copolymerizable with this monomer. or an acrylic acid ester-based graft copolymer obtained by polymerizing 10 to 1000 parts by weight of a mixture thereof [■] 1 to 99% by weight. A thermoplastic resin composition with excellent heat resistance and impact resistance. 2 , methacrylic resin, polycarbonate, AS resin, methyl methacrylate-styrene copolymer, polystyrene/, polyester, and nylon. The thermoplastic resin composition described above has excellent heat resistance and impact resistance.