JPS6038419A - Production of weather-resistant graft copolymer - Google Patents

Abstract

PURPOSE:To produce the titled copolymer excellent in weather resistance and impact resistance, by graft-copolymerizing a polymerizable monomer with an uncrosslinked saturated rubber elastomer containing an at least trifunctional oligo (acrylate ester). CONSTITUTION:An at least trifunctional oligo(acrylate ester) with MW of about 5X10<2>-1X10<4>, is formed by linking at least three acrylate ester molecules through ester bonds. 100pts.wt. uncrosslinked saturated rubber elastomer (e.g., EPDM, acrylic rubber, or ethylene/vinyl acetate copolymer) containing, if necessary, a crosslinked saturated rubber elastomer is mixed with 0.05-10pts.wt. above oligo(acrylate ester) and further mixed with about 40-90pts.wt. copolymerizable monomer (e.g., a mixture of about 40-90pts.wt. styrene and about 60-10pts.wt. acrylonitrile), and the resulting mixture is emulsion-graft-copolymerized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a graft copolymer having excellent weather resistance and impact resistance.

Ethylene-propylene-nonconjugated diene terpolymer (E
Graft copolymers obtained by graft copolymerizing styrene, acrylonitrile, etc. to saturated primary rubber elastic bodies such as PDM), acrylic rubber, butyl rubber, and ethylene-vinyl acetate copolymers.

Unlike ground copolymers (so-called ABS resins, etc.) using diene rubber elastic bodies such as polybutadiene, it has excellent weather resistance and can be used outdoors.

The appearance of molded products of such graft copolymers is obtained by emulsion polymerization.

Although preferred from the viewpoint of productivity, graft copolymers produced by emulsion polymerization have often not had sufficient impact resistance compared to those using diene rubber elastic bodies. Such a graft copolymer is composed of mu elastomer particles and θ,
It is preferable to contain two types of comb elastic particles, which are large-sized rubber elastic particles having an average particle size of about 1.0 m, from the viewpoint of improving impact resistance. In this case, latex obtained by emulsion polymerization is usually used as the small-diameter comb elastomer particles, and the latex 9 is sufficiently crosslinked during the polymerization process.

On the other hand, large-sized rubber elastic particles are used after dissolving the rubber elastic body in monomers, organic solvents, etc., and then emulsifying and dispersing them. Since the comb elasticity is cross-linked and does not exhibit sufficient shock absorption ability when it is 1/-, it is necessary to perform cross-linking in the graft polymerization process. When dimethacrylate or trimethylolpropane triacrylate is used, not only the uncrosslinked rubber elastic body but also the already crosslinked small-diameter rubber bullet particles and the continuous phase (IJ SOCS) are excessively crosslinked. Therefore, there were problems such as deterioration of the physical properties of the copolymer.

Therefore, in order to avoid this, crosslinking and graft polymerization must be insufficiently stopped, which is believed to be the reason why the impact resistance of 5 is not improved.

The present inventors have conducted extensive research with the aim of developing a method for producing a weather-resistant graft copolymer with excellent impact resistance, and have thus arrived at the present invention. , uncrosslinked saturated rubber elastic body and, if necessary, crosslinked saturated rubber elastic body, plus styrene, α-methylstyrene, p-vinyltoluene, acrylonitrile, methacrylonitrile, methyl acrylate, methyl methacrylate, vinyl chloride. and vinylidene chloride force・group 7
5) In the method for producing a V-resistant graft copolymer by emulsion graft copolymerization of at least one monomer selected from A method for carrying out the polymerization is now available.

Examples of the crosslinked and uncrosslinked saturated rubber elastic bodies used in the present invention include EPDM, acrylic rubber (acrylic acid ester copolymer)% butyl rubber, ethylene-vinyl acetate copolymer, and the like. Monomers that are graft copolymerized to the rubber elastic body to form a continuous phase of the graft copolymer include styrene, α-methylstyrene, p-vinyltoluene, acrylonitrile, methacrylonitrile, methyl acrylate, It is appropriate to use at least one monomer selected from methyl methacrylate, vinyl chloride, and vinylidene chloride in terms of heat resistance, four-drug resistance, and the like. Usually, a mixture consisting of 0 parts by weight of styrene θ and 0 parts by weight of acrylonitrile/θ.

Styrene is used.

The large-diameter rubber elastomer particles are made of an uncrosslinked saturated comb elastomer grafted with an aromatic monomer such as monofl, especially styrene, α-methylstyrene, etc. It is obtained by dissolving in a solvent such as n-hexane or n-hebutane, and then emulsifying and dispersing it in water. Unshelf 1. + things; used). If the saturated rubber elastic body is crosslinked, it will not dissolve in the Ai polymer, etc., which is not preferable. Emulsification and dispersion is carried out using a suitable surfactant and stirring and mixing using a machine.In particular, at first, a small amount of water is added to the rubber elastomer solution and H
A surfactant with a small LB value is used to create a W/O type (dispersed phase/continuous phase, W: water phase, 0: oil phase, the same applies hereafter) emulsion, and water is added to create a 0/O type emulsion. It is preferable to form an emulsion of W.
.

Before emulsifying and dispersing the uncrosslinked saturated rubber elastomer solution, trifunctional or higher functionality olicoester acrylate is mixed in advance. Olicoester acrylate is suitable for mixing 0.05 to 10 parts by weight, preferably 0 to 2 parts by weight, based on the uncrosslinked saturated comb elastic body 10θ weight = ++. Oligoester acrylate is an oligoester (oligoθ5ter) with a molecular weight of jX702 to /x70', with 3 acrylic acids per molecule.
A molecule that has more than one ester bond is called a molecule. If acrylic acid/or one molecule of acrylic acid is used,
Sufficient fjf resistance as physical properties of the resulting graft copolymer
This is not preferable because it is difficult to obtain good impact performance.

If the amount of oligoester acrylate mixed with the uncrosslinked saturated rubber elastic body is less than θ, θj weight, sufficient crosslinking effect will not be obtained, and if it exceeds 100 parts by weight, excessive crosslinking will result, resulting in poor performance. This is not preferable because the one-time impact strength of the graft copolymer is not sufficiently improved.

Oligoester acrylate has a larger molecular weight than other crosslinking agents, and has extremely low solubility in water, so it is difficult to absorb the monomers and crosslinked rubber elastomer particles that form the continuous phase in the graft polymerization process. This is suitable because it does not cause excessive crosslinking of stiffness, etc., and therefore does not deteriorate the physical properties of the obtained graft copolymer.

If the oligoester acrylate is added after the undyed % Ij rubber elastic body solution has been emulsified and dispersed, the oligoester acrylate will not be sufficiently contained in the uncrosslinked rubber elastic body, but will be further contained in other polymerization components, which is preferable. do not have.

During ground copolymerization, a necessary amount of cross-linked saturated rubber elastomer latex produced by an emulsion polymerization method is added as a small-particle saturated rubber elastomer component to the emulsion obtained by the above method to obtain appropriate rubber elasticity. Granod copolymers with a uniform particle size distribution can be produced in one step. The small particle diameter rubber elastic latex used here is preferably crosslinked during the latex manufacturing process. Other conditions for emulsion graft copolymerization are conventional methods, especially JP-A No. 7-/9
This can be carried out by the method described in Publication No. 9/J.

According to the method of the present invention, a graft copolymer having sufficient impact resistance and weather resistance can be easily obtained and has great industrial utility value.

The present invention will be explained in more detail based on Examples and Comparative Examples.

Example/ (Manufacture of EPDM emulsion) A spark type stirring device was equipped. Styrene 12θ9. in a 2t flask. EPDM (Nippon Ehi Rubber (manufactured by (1), BP-33)/3θ2, oil-soluble emulsifier (manufactured by Hiroshi Kogyo Seiyaku ■), itenol N-θ?) 9.739 and water 32
．． jml and stirred for 3 hours at SS°C under an indoor atmosphere to uniformly dissolve. Subsequently, "Aroex M-2/θ0" manufactured by Toagosei Chemical Industry Co., Ltd., as a polyfunctional oligoester acrylate was added to the mixture for 90 minutes and stirred to dissolve.

The resulting W10 type emulsion was added to the water with stirring for 3 fs minutes. Further, water from SZ was added all at once to transform the phase into an O/W emulsion. The particle size of B PDM in the obtained emulsion is θ, and μ7+i
(measured by Coulter counter).

(Manufacture of polyacrylic acid ester copolymer latex) 202 (Na salt of hardware), NaHCO, /θ7 were charged and the temperature was raised to 7 J-°C under a nitrogen stream. Here, add 38 potassium sulfate (KPS) to θ, 7 j! Contains 20 ml of water
Add, stir, and! minutes later, butyl acrylate 937,
Among the monomer mixtures consisting of j f , acrylonitrile A-λ, A-2, and A-2, Gθ2 was added all at once. After about a minute, the temperature started to rise slowly. Addition of monomer mixture/K after evening
A PS aqueous solution of 0.2off/2θm1 (KPS/water and below) was added, and at the same time, the remaining amount of the monomer mixture was continuously added over 2.5 hours.

Incidentally, fat/acid soap Otsu 2 was added after i and s time elapsed after the start of continuous addition. After the addition of the monomer mixture was completed, the same temperature was maintained to complete the polymerization.

Conversion rate (weight ratio), average particle size θ, 0 μ? It was 71.

Pour half of the obtained latex into another 3t flask and add 1 tsp of water. j” ml and mixed with sodium dodecylbenzenesulfonate (DBEI) /θti aqueous solution j2, 50
It was kept at ℃. To this, 23% by weight H3PO4 aqueous solution 3
．． Add 209 for 7 minutes, leave for 6 minutes with gentle stirring, then 2! % KOH aqueous solution 2.2. 2 and DBS
2 Tachi aqueous solution/Li 2 was added and stirred thoroughly. The average particle size was 0.23 μm (measured by nanosizer)
.

(Production of graft copolymer) The above polyacrylic acid ester copolymer latex/2θ27 was charged into a 3-t flask and the temperature was raised to 0°C. Subsequently, KPS/f was dissolved in 2 liters of water and added, and at the same time, the above E PDM emulsion Otsu 7/, 3 S'
and KPEI aqueous solution (3,3f,,/'torime)
The addition was continued over a period of 7 hours and 20 minutes.

Then, styrene 2/θ2 and acrylonitrile 2θ2
The mixture was added continuously over a period of 2 hours.

After the start of addition of EPDM emulsion, after 3θ minutes, fat 2/2θ- and 42 hours, high-quality clothes/acid soap aqueous solution x, Tough f/20-, and Terpirsin L, 3 B
f were added respectively. 30 minutes after addition of monomer-contaminated compound
Minutes? Polymerization was completed after maintaining the temperature at θ°C. Add salt to cacz2, wash with water, dry, and! '3θ2 graft copolymer was obtained.

The obtained graft copolymer was coated with an As resin (acrylonitrile content: 2≦N%) to have a rubber elastic body content of 20% by weight, and the physical properties were as follows.

Izotsu impact strength-1 (JIS K4/7/) 29
9cm/cm tensile strength (〃)ri001cg/cr
! Melt flow index /, 5-9710 minutes (+
22θ℃, /θ/cg, JISK 70) Example 2 (Production of EPDM-containing graft copolymer) Water in a /l flask, 200rnI! Prepared in nitrogen! The temperature started to rise to θ℃. To this, KPS aqueous solution o, 419/'l Om
At the same time, continuous addition of KPDM emulsion Otsu 2/2 obtained in Example/ was started.

Addition was completed in 3 hours. In addition, the KPS aqueous solution was 0.9 hours after the start of addition and after 2 hours! f/', 10
- were added respectively. After the addition of the KPDM emulsion was completed, the polymerization continued for another hour and the conversion rate was 9.

(Production of polyacrylic acid ester-containing graft copolymer) After 23 minutes, 1'2 of the polyacrylic acid ester graft copolymer latex obtained in Example 1 was added to a 3-ton flask, and the temperature was raised to 0°C. is.

KPS aqueous solution/! ? l f//jθ- was added, and at the same time 50 g of styrene Otsu, 27♂ of acrylonitrile, Otsu 2
A mixture consisting of was continuously added. 7.5 after starting continuous addition
From the point when 'minutes have elapsed, KPS! ;1. f 7 f water/
Continuous addition of solution dissolved in guar'rnl was started.

Jt% KO) 1 aqueous solution/l, 3 f at 30 minutes after the start of monomer addition, luxury clothes 11 at 70 minutes after the start of monomer addition
/, i-'F5 soap aqueous solution Gutaka 92/3 O, and after the same time, Terpilcin J, f79 were added, respectively. The continuous addition of KPS and the monomer mixture was completed in 3 hours < tS minutes, and the reaction was then maintained at goC for 30 minutes to complete the reaction.

The conversion rate was 9, which was high.

(Graft copolymer composition) The above two types of graft copolymers were blended so that the rubber elastic material content was 20% by weight.

The physical properties measured in the same manner as in Example/ were determined in the following manner.

Izot impact strength 20 to 9 cm/cm Tensile strength 00/ctj/ca Melt flow index A graft copolymer was obtained in the same manner as in Example 1, except that 2 groups (containing 2 groups) oligoester acrylate, ``Arrotx M-t ¥20J'' manufactured by Toagosei Kagaku Kogyo ■ was used.

The physical properties obtained in the same manner as in Example were as follows.

Izot impact strength 73 kgcm/(7) Tensile strength 390 Noah 9/crl Melt flow index /71/10 minutes Comparative example - Trimethylolpropane triacrylate 6.3'2 was used instead of oligoester acrylate as a crosslinking agent. Except for this, the graft copolymer was prepared in the same manner as in Example 1. ")is.

The physical properties were as follows.

Izot impact strength / 3 kg on10n tensile strength θθ / C & / cn\melt flow rodex // ? / 10 minutes Direct access to patent filing Mitsubishi Monsanto Chemicals Co., Ltd. Representative Patent attorney - Flexibility 1. -
(and 7 others) Procedural amendment (voluntary) l Indication of the case 1937 Patent Application No. 1 Ko 7, 7
#; No. 2 Name of the invention Process for producing a weather-resistant graft copolymer 3 Relationship with the case of the person making the amendment Name of patent applicant (Aoa) Mitsubishi Monsanto Chemical Co., Ltd. 4 agents 〒100 5 Subject of amendment of the specification Detailed Description of the Invention Column 6 Contents of the Amendment (1) The following sentence is inserted following the 20th line of the second page of the specification.

Rubenzene sulfo/acid soda t'yt, water 1.11
Separately prepare an emulsion consisting of m1, and add the above EPD
It was mixed with M Emulsion 30/f to obtain an emulsion containing styrene, acrylonitrile, EPDM, and oligoester acrylate. (2) Line 77 of page 1 of the specification is corrected as follows.

1♂41 ml) was added continuously over 7 hours and 20 minutes. "· that's all

Claims (2)

[Claims] (1) Styrene, α-methylstyrene, p-vinyltoluene, acrylonitrile, methacrylonitrile, methyl acrylate, methyl methacrylate in addition to an uncrosslinked saturated rubber elastic body and a crosslinked saturated rubber elastic body as necessary. , a method for producing a weather-resistant graft copolymer by emulsion graft copolymerization of at least one monomer selected from the group consisting of vinyl chloride and vinylidene chloride, wherein 700 parts by weight of the above-mentioned uncrosslinked saturated rubber elastic body; trifunctional or higher functional oligoester acrylate 1-0.0 j~
A method characterized in that both are mixed in advance in a ratio of parts by weight of IO, and then emulsion graft polymerization is performed. (2) Claim 1, wherein the uncrosslinked saturated rubber elastic body is at least seven rubber elastic bodies selected from the group consisting of ethylene-propylene-nonconjugated diene terpolymer, acrylic rubber, and butyl rubber. The method described in section.