JP2001131429A - Impact resistance improver with improved anti-block properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide graft copolymer compositions having excellent anti-block properties without any deterioration of the impact resistance improving effect on thermoplastic resins. SOLUTION: The graft copolymer compositions are obtained by rendering 100 pts.wt. graft copolymer latex having a hollow rubber component a solidified slurry and then, mixing 0.1-10 pts.wt. crosslinked polymer obtained by polymerizing 0.1-100 wt.% crosslinkable monomer and 0-99.9 wt.% vinyl type monomer with the resulting slurry in the state of a latex or a solidified slurry.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in blocking resistance of an impact modifier powder resin for a thermoplastic resin.

[0002]

2. Description of the Related Art Various proposals have conventionally been made to improve the impact resistance of a thermoplastic resin. Craze and shear yield play an important role in improving the impact resistance, but stress concentration in the molded body is indispensable for their generation, and therefore, a graft copolymer containing a rubber component is blended. Improving impact resistance has been widely practiced. It is predicted that making holes in this rubber component will have a greater effect on the degree of stress concentration (Ikuo Narusawa, “Impact resistance of plastics”, 131, 155, Sigma Publishing Co., Ltd.). You can expect sex. For these reasons, studies have recently been made to improve the impact resistance of a thermoplastic resin using a graft copolymer having a hollow rubber component.

For example, Japanese Patent Application Laid-Open No. 10-310714 proposes a method of synthesizing a hollow rubber graft copolymer by utilizing a hollow particle synthesizing technique to improve the impact resistance of a thermoplastic resin.

[0004]

When the above graft copolymer is used, the impact resistance is more advantageous than that of a graft copolymer using a solid rubber component. Since the softening temperature of the coalescence is low, there arises a problem that powder characteristics such as blocking resistance deteriorate.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on the above-mentioned problems, and as a result, when a crosslinked polymer is blended with a graft copolymer using a hollow rubber component, the powder characteristics are extremely high. It has been found that a good graft copolymer composition can be obtained, and the present invention has been completed.

That is, according to the present invention, 100 parts by weight (solid content) of a graft copolymer latex using a hollow rubber component is converted into a coagulated slurry, and then 0.1 to 100% by weight of a crosslinkable monomer and a vinyl monomer Impact modifier for thermoplastic resin obtained by mixing 0.1 to 10 parts by weight of a crosslinked polymer obtained by polymerizing 0 to 99.9% by weight of a polymer in the form of a latex or a coagulated slurry (Claim 1) And the crosslinked polymer is 30 to 60% by weight of methyl methacrylate, and the aromatic vinyl monomer 65 to 65 is used.
A thermoplastic polymer according to claim 1, which is a crosslinked polymer obtained by polymerizing 35% by weight, 0.1 to 25% by weight of a crosslinkable monomer and 0 to 30% by weight of another copolymerizable monomer. The present invention relates to an impact modifier (Claim 2).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hollow rubber particles are different from conventional rubber particles in which the whole particles are formed of a rubber component.
It has a rubber component non-filled portion inside the rubber particles. There are several ways to synthesize hollow rubber particles. For example, (a) a method of synthesizing a W / O / W (O: lipophilic, W: hydrophilic) emulsion and polymerizing the monomer of the O layer,
(B) a method in which core-shell particles having a swellable core are swelled at a temperature equal to or higher than the glass transition temperature (Tg) of the shell layer to make them hollow, (C) a method by two-stage polymerization of polymers having different solubility parameters, (D) a method in which a polymerizable monomer containing a crosslinking monomer and a hydrophilic monomer and an oily substance are finely dispersed in water to form an O / W emulsion, and the monomer is polymerized to remove the oily substance; A method utilizing the transfer of a polymerized carboxylic acid in particles under acid and alkaline conditions is known ("Application of Synthetic Latex", Takaaki Sugimura et al., P. 285).

[0008] The rubber particles having a hollow state in the latex state of the present invention may be produced by any method, and the method is not particularly limited.

Examples of the seed polymer of the hollow rubber component include rubbers such as diene rubber, acrylic rubber, silicon rubber and olefin rubber, butyl acrylate-styrene copolymer, ethyl acrylate-styrene copolymer and the like. Having a rigid polymer such as a semi-rigid polymer or a styrene-methyl methacrylate copolymer as a skeleton, and using a chain transfer agent such as t-dodecyl mercaptan or n-dodecyl mercaptan in order to reduce the molecular weight.

The hollow rubber component used in the present invention is preferably a rubber elastic body having a Tg of 0 ° C. or less, and more preferably a lower Tg. As the rubber component, for example, diene rubber, acrylic rubber, silicon rubber,
There are olefin-based rubbers, but not limited to these. Examples of the diene rubber include butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, and the like, and examples of the acrylic rubber include butyl acrylate rubber, butadiene-butyl acrylate rubber, and 2-ethylhexyl acrylate-butyl acrylate rubber.
Examples of the silicone rubber include polydimethylsiloxane rubber, and examples of the olefin rubber include ethylene-propylene rubber and ethylene-propylene-diene rubber.

The crosslinkable monomer used for rubber polymerization functions to prevent the rubber particles from falling apart during molding.
If the amount is too large, the molded article does not collapse at the time of molding, but when the molded article is subjected to impact (under stress), the voids do not easily spread, and the impact strength of the molded article is not significantly improved.

Examples of the crosslinkable monomer include allyl methacrylate, divinylbenzene, diallyl phthalate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, and ethylene glycol dimethacrylate.

[0013] The graft copolymer using the hollow rubber component may be obtained by directly polymerizing a vinyl monomer to the hollow rubber particles to obtain a graft polymer, or may be used for acid enlargement or salt enlargement of the hollow rubber particles. Larger graft polymers can also be obtained by bloat technology. After embedding the rubber latex with epoxy resin, the void of the rubber particles hollow in the latex state,
It can be confirmed by TEM observation after staining with ruthenium tetroxide or the like. Further, after the rubber latex particles are accurately obtained by Microtrac UPA or the like, the porosity can be calculated by measuring the light scattering intensity of the same rubber latex. The porosity of the hollow rubber in the latex state is 3 to 90% by weight, preferably 10 to 60% from the viewpoint of the effect of improving the impact resistance of the molded article. If the porosity exceeds 90%, the rubber particles may collapse during molding, and the impact strength cannot be stably improved. If the porosity is less than 3%, the generation and expansion of voids in the rubber when the molded article is subjected to an impact is difficult to progress, and the effect of improving the impact resistance is reduced.

In order to maximize the effect of improving the impact resistance of the molded article, the particle size of the graft copolymer of the present invention must be
The optimum value varies depending on the type of thermoplastic resin,
It is preferably in the range of 5 to 2.0 μm. Outside this range, the effect of improving the impact resistance is reduced. The synthesis of the hollow rubber is not particularly limited, but can be efficiently performed by using an emulsion polymerization method.

The graft copolymer of the present invention is preferably used in an amount of from 30 to 90 parts by weight, more preferably from 60 to 90 parts by weight of the hollow rubber component.
Vinyl monomer in the presence of 85 parts by weight, preferably 10 to
It is obtained by polymerizing 70 parts by weight, more preferably 15 to 40 parts by weight. If the amount of the hollow rubber component is less than 30 parts by weight, the effect of improving the impact resistance is small, and if it exceeds 90 parts by weight, the effect of improving the impact resistance of the molded article tends to be reduced due to the collapse of the graft copolymer particles during molding.

Examples of the vinyl monomer include (meth) acrylic acid esters, aromatic vinyl compounds, vinyl cyanide compounds, vinyl chloride compounds and the like. Examples of the (meth) acrylate include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. Examples of the aromatic vinyl compound include styrene, α-methylstyrene, chlorostyrene and the like. Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile.

The crosslinked polymer is a crosslinkable monomer of 0.1 to 10
It is obtained by polymerizing 0% by weight and 0 to 99.9% by weight of a vinyl monomer to improve the blocking resistance of the graft copolymer. The average particle size of the crosslinked polymer is preferably 50 from the viewpoint that the effect of improving blocking resistance is large.
５００500 nm, more preferably 100-300 nm, even more preferably 110-250 nm. The crosslinkable monomer forms a crosslinked structure of a crosslinked polymer, and is a polyfunctional monomer containing two or more polymerizable unsaturated bonds. Specific examples thereof include a crosslinker for the rubber component. Items. Specific examples of the vinyl monomer used for the crosslinked polymer include the same vinyl monomers used for the graft polymerization of the graft polymer. In particular, a homopolymer obtained from a monomer having a Tg of 20 ° C. or higher is preferable. Specific examples thereof include methyl methacrylate, butyl methacrylate, styrene, aromatic vinyl monomers such as α-methylstyrene, acrylonitrile,
And vinyl cyanide monomers such as methacrylonitrile. These may be used alone or in combination of two or more.

In the production of the crosslinked polymer, the proportion of the monomer used is 0.1 to 100% by weight of the crosslinkable monomer and 0 to 99.
9% by weight. Furthermore, when blended in a vinyl chloride resin, the crosslinking monomer 0.1 to
25% by weight, 30-60% by weight of methyl methacrylate,
The content is preferably 65 to 35% by weight of an aromatic vinyl monomer and 0 to 30% by weight of another vinyl monomer.

The crosslinked polymer can be obtained by a usual emulsion polymerization method using a radical polymerization initiator and, if necessary, a chain transfer agent.

In the production of the graft copolymer and the crosslinked polymer, a radical polymerization initiator and, if necessary, a chain transfer agent are used, but these are not particularly limited as long as they are used in ordinary radical polymerization.

Specific examples of the radical polymerization initiator include cumene hydroperoxide, t-butyl peroxide, benzoyl peroxide, t-butylperoxyisopropyl carbonate, di-t-butyl peroxide, t-butyl laurate, lauroyl. Organic peroxides such as peroxyside, succinic peroxide, cyclohexanone peroxide, and acetylacetone peroxide; inorganic peroxides such as potassium persulfate and ammonium persulfate; 2,2′-azobisisobutyronitrile; An azo compound such as 2′-azobis-2,4-dimethylvaleronitrile is exemplified. this house,
Organic peroxides or inorganic peroxides are preferred because of their high reactivity. When an organic peroxide or an inorganic peroxide is used, ferrous sulfate / glucose / sodium pyrophosphate, ferrous sulfate / dextrose / sodium pyrophosphate or ferrous sulfate / sodium formaldehyde sulfoxylate / ethylenediamine acetate, etc. The mixture can be used as a reducing agent. The combined use of a reducing agent is preferred because the polymerization temperature can be lowered.

The amount of the radical polymerization initiator used is usually 0.00
It is preferably 5 to 10 parts by weight.

If the amount of the radical polymerization initiator is small, the polymerization rate tends to be low and the productivity tends to be low. If the amount is too large, the molecular weight of the obtained polymer is low and the impact resistance or the powder properties are low. There is a tendency.

Specific examples of the chain transfer agent include t-dodecyl mercaptan, n-octyl mercaptan, n-tetradecyl mercaptan, n-hexyl mercaptan and the like.

The chain transfer agent is an optional component, but when used, the amount of the chain transfer agent may be one monomer in total in view of the development of impact resistance.
It is preferably 0.001 to 5 parts by weight based on 00 parts by weight.

The graft copolymer and the crosslinked polymer are recovered by coagulating a latex of the graft copolymer to form a coagulated slurry having a solid content of about 5 to 40% by weight, and adding the latex of the crosslinked polymer. Alternatively, a latex of a graft copolymer is coagulated to form a slurry having a solid content of about 5 to 40% by weight, and a latex of a crosslinked polymer is coagulated to form a coagulated slurry having a solid content of about 5 to 40% by weight. The method of adding and recovering has a large blocking resistance improving effect.

The mixing ratio of the graft copolymer and the crosslinked polymer is 0.1 to 1 with respect to 100 parts by weight of the graft copolymer based on the balance between impact resistance and blocking resistance.
0 parts by weight. If the amount of the crosslinked polymer is too small, the effect of improving the blocking resistance tends to be small,
If the amount is too large, the impact resistance tends to decrease.

An impact modifier for a thermoplastic resin comprising the graft copolymer and the crosslinked polymer thus obtained is obtained.

The impact resistance improver for thermoplastic resin can improve the impact resistance of the thermoplastic resin by being mixed with various thermoplastic resins.

Specific examples of the thermoplastic resin include polyvinyl chloride, chlorinated polyvinyl chloride, polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-N-phenylmaleimide copolymer, and α-methylstyrene-acrylonitrile copolymer. Coalesce, polymethyl methacrylate, methyl methacrylate-styrene copolymer, polycarbonate, polyamide, polyethylene phthalate,
Examples thereof include polyesters such as polybutylene phthalate, polyphenylene ethers, and the like. These may be used alone or in combination of two or more.

The mixing ratio of the thermoplastic resin and the impact modifier is 5 to 99 parts by weight, preferably 10 to 97 parts by weight of the thermoplastic resin.
It is preferable that the impact resistance improver is used in an amount of 1 to 95 parts by weight, preferably 3 to 90 parts by weight with respect to parts by weight, because the molded article has good impact resistance and rigidity. The mixing of the impact resistance improver and the thermoplastic resin can be performed by mixing with a Henschel mixer, a ribbon blender or the like, and then mixing with a roll, an extruder, a kneader or the like.

At this time, commonly used compounding agents, that is, plasticizers, stabilizers, lubricants, ultraviolet absorbers, antioxidants, flame retardants, pigments, glass fibers, fillers, polymer processing aids, polymer lubricants And the like.

As a molding method of the obtained thermoplastic resin composition, a usual thermoplastic resin molding method, for example, an injection molding method, an extrusion molding method, a blow molding method, a calender molding method and the like can be applied.

[0034]

EXAMPLES Hereinafter, the present invention will be described with reference to specific examples, but these examples do not limit the present invention. Unless otherwise specified, "parts" in the examples indicate parts by weight and "%" indicates% by weight.

The evaluation in the following Examples and Comparative Examples was performed according to the following methods. [Blocking resistance] Powder 3 of graft copolymer composition
0g in a 50mm diameter cylindrical container, 1kg at 40 ℃
/ Cm ² for 3 hours to make a block, and the block is collapsed by applying a vibration of 60 Hz for 100 seconds with a powder tester PEE manufactured by Hosokawa Micron Corporation, and the whole powder of the powder passed through an 18 mesh sieve. The ratio to body weight was determined. The higher the value, the higher the blocking resistance. [Izod impact strength] According to JIS K7110,
Measured at 23 ° C. using a notched ４ inch bar.

The following thermoplastic resins were used in the examples. Polyvinyl chloride (Kanevinyl S-4)
00: manufactured by Kanegabuchi Chemical Industry Co., Ltd.)
VS8831: 3.0 parts by Nitto Kasei Co., Ltd .; 0.5 parts of lubricant (Hoechstwa E: manufactured by Hoechst); polymer processing aid (Kaneace PA-20: manufactured by Kanegafuchi Chemical Industry Co., Ltd.) 1
The part is blended. The molding of the thermoplastic resin composition comprising the thermoplastic resin and the graft copolymer composition was performed as follows.

Single screw extruder (VS 50 m / m extruder:
(Tanabe Plastics Machine Co., Ltd.) at 155 ° C. to produce pellets. An injection molding machine (IS-17) in which the obtained pellet was set at a cylinder temperature of 175 ° C.
0G: Toshiba Machine Co., Ltd.).

Example-1 [Graft copolymer having hollow rubber component] (1) Production of seed part of rubber latex 200 parts of water, 3.5 parts of sodium oleate, and potassium phosphate
0.4 parts, formalin β-naphthalenesulfonic acid
0.2 parts of sodium salt of the compound
0.005 parts of disodium acetate, ferrous sulfate (FeSO
_Four・ 7H_TwoO) 0.002 parts, t-dodecyl mercaptan
10 parts, 25 parts of styrene and 75 parts of butadiene are mixed,
After heating to 50 ° C, paramenthan hydroperoxide
0.1 part, sodium formaldehyde sulfoxylate
And polymerized for 15 hours.
A 0.06 μm rubber latex (R-1) was obtained. (2) Production of Graft Copolymer Having Hollow Rubber Component Rubber latex (R-1) 10 parts (solid content) and water 70 parts
Mixed. 75 parts of butyl acrylate and allyl
7.5 parts of acrylate, 19 parts of toluene, 5% lauryl
0.75 parts (solid content) of sodium sulfate aqueous solution, 400 parts of water
The mixture was added finely by a homogenizer and added at room temperature.
For 2 hours. Ferrous sulfate (FeSO _Four・ 7H_TwoO)
0.002 parts, sodium diamine ethylenediaminetetraacetate
0.005 parts, formaldehyde sulfoxylate
0.2 parts thorium, paramenthane hydroperoxide
1 part was added, and polymerization was carried out at 40 ° C. for 2 hours. Heated to 45 ° C
After that, 0.15 parts of a 5% aqueous sodium lauryl sulfate solution
(Solid content), ferrous sulfate (FeSO_Four・ 7H_TwoO) 0.00
16 parts, disodium ethylenediaminetetraacetate 0.1.
004 parts, sodium formaldehyde sulfoxylate
Of methyl methacrylate 13.2
Parts, 1.8 parts of butyl methacrylate and cumene hydro
A mixture of 0.012 parts of peroxide was added continuously over 1 hour.
After the addition, polymerization was carried out for 1 hour, and the average particle diameter was 0.13.
μm hollow graft copolymer latex (G-1)
Was. [Production of crosslinked polymer (L-1)] 200 parts of water, olein
0.5 part acid soda, ferrous sulfate (FeSO_Four・ 7H_TwoO)
0.002 parts, sodium diamine ethylenediaminetetraacetate
0.005 parts of sodium formaldehyde sulfoxylate
Charge 0.2 parts of thorium into a polymerization vessel equipped with a stirrer,
℃, 80 parts of methyl methacrylate, styrene
10 parts of len, 1,3-butylene glycol dimethacrylate
10 parts, 0.3 parts of cumene hydroperoxide
The mixture was continuously added in 7 hours. During the second hour, 4:00
Add about 0.5 parts of sodium oleate each time between 6 and 6 hours
Was. After the addition of the monomer mixture, post-polymerization was performed for 2 hours.
Polymer latex (L-1) having a polymerization conversion of 99%
I got [Production of impact modifier] Hollow graft copolymer (G-
5% calcium chloride is added to 100 parts (solid content) of latex of 1).
80 parts of an aqueous solution of water and solidified.
To obtain a solidified slurry with an average particle size of 200 μm
Was. While stirring the obtained solidified slurry, the crosslinked polymer
One part of the latex of (L-1) is added as a solid content,
Dewatering and drying after heat treatment for 5 minutes at
A powder of an impact resistance improver having a diameter of 100 μm was obtained. Got
For blocking resistance and thermoplastic resin of impact modifier
Table 1 shows the Izod impact strength of the molded product obtained by blending.
You.

[0039] Example 2 [crosslinked polymer (L-2) of the production] 200 parts of water, oleic oxygen - da 0.5 parts of ferrous sulfate (FeSO ₄ · 7H ₂ O)
0.002 parts, 0.005 parts of disodium ethylenediaminetetraacetate and 0.2 parts of sodium formaldehyde sulfoxylate were charged into a polymerization vessel equipped with a stirrer,
After the temperature was raised to ° C., a mixed solution of 35 parts of methyl methacrylate, 45 parts of styrene, 20 parts of 1,3-butylene glycol dimethacrylate, and 0.3 part of cumene hydroperoxide was continuously added over 7 hours. During this time, 0.5 parts each of sodium oleate was added at the second, fourth and sixth hours. After the addition of the monomer mixture, post-polymerization was performed for 2 hours, and a polymer latex (L-2) having a polymerization conversion rate of 99% was obtained.
I got [Production of impact modifier] Hollow graft copolymer (G-
To 100 parts (solid content) of the latex of 1), 80 parts of a 5% calcium chloride aqueous solution was added to coagulate, and 300 parts of pure water was further added.
The resulting mixture was added to obtain a solidified slurry having an average particle diameter of 200 μm. One part of the latex of the crosslinked polymer (L-2) was added as a solid content while stirring the obtained solidified slurry, and the powder of Example-2 was obtained in the same manner as in Example-1.

Example 3 A powder of Example 3 was obtained in the same manner as in Example 2, except that 3 parts of a solid content of the latex of the crosslinked polymer (L-2) was added. Was.

Comparative Example 1 Evaluation was made in the same manner as in Example 1 except that the crosslinked polymer (L-1) was not added.

Comparative Example 2 In the preparation of a graft copolymer having a hollow rubber component, 10 parts (solid content) of rubber latex (R-1) and 70 parts of water, 5%
0.75 parts of sodium lauryl sulfate aqueous solution (solid content), ferrous _{(FeSO 4 · 7H 2 O)} 0.002 parts of sulfuric acid, ethylenediaminetetraacetic acid disodium 0.005 parts, 0.2 parts formaldehyde sulfoxylate sodium hexyl acid , And 75 parts of butyl acrylate, 7.5 parts of allyl methacrylate and 1 part of paramenthane hydroperoxide were continuously added at 40 ° C. in 5 hours. Having a graft copolymer (G-2). The latex of this non-hollow graft copolymer (G-2) was used in an amount of 100 parts (solid content).
In the same manner as in Example 2, a powder of an impact modifier was obtained.

From Table 1, it can be seen that the impact modifier comprising the crosslinked polymer and the graft copolymer of the present invention has an excellent balance between the powder characteristics and the impact resistance improving effect.

[0044]

[Table 1]

[0045]

According to the present invention, it is possible to obtain a graft copolymer composition having an excellent balance between the powder characteristics and the impact resistance improving effect.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Akira Takagi 1-8 Takasaki, Miyakomachi, Takasago-cho, Takasago, Hyogo Prefecture F-term (reference) 4J002 AC032 AC072 AC082 BB152 BC013 BC031 BC034 BC061 BC071 BC091 BC094 BC101 BC114 BD041 BD181 BG042 BG043 BG044 BG051 BG053 BG054 BG104 BK003 BN031 BN121 BN141 BN201 CF061 CF071 CG001 CH071 CL001 CP032 FA102

Claims (2)

[Claims] 1. 100 parts by weight (solid content) of a graft copolymer latex using a hollow rubber component is converted into a coagulated slurry, and then 0.1 to 100% by weight of a crosslinkable monomer and 0 to 99% of a vinyl monomer. An impact modifier for a thermoplastic resin obtained by mixing 0.1 to 10 parts by weight of a crosslinked polymer obtained by polymerizing 9.9% by weight in the form of a latex or a coagulated slurry. 2. The crosslinked polymer is methyl methacrylate 30.
~ 60% by weight, aromatic vinyl monomer 65-35% by weight,
The impact modifier according to claim 1, which is a crosslinked polymer obtained by polymerizing 0.1 to 25% by weight of a crosslinkable monomer and 0 to 30% by weight of another vinyl monomer.