JPS62109812A - Production of vinyl chloride graft copolymer - Google Patents

Abstract

PURPOSE:To obtain the titled copolymer having improved molding and processing properties and impact resistance, by grafting a vinyl chloride monomer or a mixture of it and a comonomer onto an ethylene-alkyl acrylate copolymer in the presence of a chain transfer agent. CONSTITUTION:A vinyl chloride monmer or it and a monomer copolymerizable with the vinyl chloride monomer are grafted onto an ethylene-alkyl acrylate copolymer resin in the presence of a chain transfer agent at 25-80 deg.C, to give the aimed graft copolymer. The ethylene-alkyl acrylate copolymer resin preferably has 1-50wt% ethyl acrylate content and 0.5-500g/10min melt flow rate and the amount of it used is preferably 1-30wt% based on the formed graft copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for suspension polymerization of vinyl chloride-based graft copolymers. More specifically, ethylene-alkyl acrylate copolymer resin (hereinafter referred to as
It's called EA. ) with a vinyl chloride monomer or a mixture of vinyl chloride and a monomer copolymerizable with it (hereinafter referred to as vinyl chloride monomer).
EA or EA-vinyl chloride graft copolymer, which is obtained by graft copolymerizing EA with a vinyl chloride monomer, is widely used as a reinforcing agent to improve the impact strength of vinyl chloride resin by mixing it with vinyl chloride resin. Are known.

However, when a composition in which EA is simply mixed with vinyl chloride resin is molded, the resulting molded product undergoes phase separation due to poor compatibility between EA and vinyl chloride resin, resulting in poor impact strength. There is also a problem that EA obtained by ordinary graft copolymerization has the problem of not being sufficiently expressed.
- When a composition in which a vinyl chloride graft copolymer is mixed with a vinyl chloride resin is molded, the impact strength is considerably improved, but there is a problem in molding processability, which poses a practical problem.

The present inventors have conducted extensive research in order to solve the above-mentioned problems of an EA-vinyl chloride copolymer obtained by graft copolymerizing a vinyl chloride monomer to EA.

As a result, when graft copolymerizing a vinyl chloride monomer to EA, by adding a chain transfer agent to the polymerization system and performing the graft copolymerization, a graft copolymer with excellent moldability and impact resistance can be obtained. The present invention was completed based on this knowledge.

As is clear from the above description, an object of the present invention is to provide a method for producing a vinyl chloride-based graft copolymer that can obtain a vinyl chloride-based graft copolymer that has extremely excellent moldability and impact strength. That's true.

The present invention has the following configuration.

A vinyl chloride system characterized by graft copolymerizing a vinyl chloride monomer or a vinyl chloride monomer and a monomer copolymerizable therewith to an ethylene-alkyl acrylate copolymer resin in the presence of a chain transfer agent. Method for producing graft copolymer.

Conventionally, it is well known that when performing radical suspension polymerization of vinyl chloride monomers, a chain transfer agent is added to the polymerization system in order to obtain a polymer with a low degree of polymerization at a relatively low polymerization reaction temperature. . However, in order to improve the moldability and impact resistance of the graft copolymer obtained when graft copolymerizing a vinyl chloride monomer to EA, a chain transfer agent is added to the polymerization system to adjust the grafting efficiency. Until now, nothing has been known about graft copolymerization reactions.

The graft efficiency of the vinyl chloride graft copolymer obtained by the production method of the present invention is about 30% by weight, and the graft efficiency of the vinyl chloride graft copolymer obtained by the conventional production method without adding a chain transfer agent is It is approximately 45% by weight.

In the EA-vinyl chloride graft copolymer produced by the production method of the present invention, the EA content is 1 to 30% by weight, preferably 5 to 15% by weight. Further, the content of alkyl acrylate in the EA is 1 to 50% by weight, preferably 10 to 40% by weight, and the melt flow rate is preferably 0.5 to 500.9/10 minutes.

The alkyl acrylate in the EA used in the present invention is an alkyl acrylate having 1 to 18 alkyl carbon atoms, but an alkyl acrylate having 2 carbon atoms, that is, ethyl acrylate is particularly preferred from the viewpoint of improving impact strength.

In the present invention, examples of monomers copolymerizable with vinyl chloride monomer include ethylene, propylene, vinyl acetate, etc., and the amount used is relative to the vinyl chloride monomer. 20 weight - or less is preferred.

The chain transfer agent used in the present invention can be exactly the same as the chain transfer agent used when polymerizing monomers capable of radical polymerization such as vinyl chloride. (1) Saturated hydrocarbons such as n-penkune, n-hexane, etc. (2) Saturated or unsaturated such as carbon tetrachloride, trichloroethylene, perchloroethylene, butyl chloride, isopropyl chloride, chloroform, carbon tetrabromide, chlorobenzene, etc. halogenated hydrocarbons, (3) alcohols such as methyl alcohol and n-butyl alcohol, (4) acetaldehyde, propionaldehyde,
Aldehydes such as n-butyraldehyde, (5)
Ketones such as cyclohexanone and methyl ethyl ketone, (6) Esters such as ethyl acetate and butyl acetate, (ethers such as catetrahydro-7), (8) Aromatic compounds such as benzene, toluene, and tetrahydronaphthalene, (9) Sulfur-containing alcohols such as 2-mercaptoethanol, 2-mercaptopropanol, thiopropylene glycol, and thioglycerin; sulfur-containing carboxylic acids such as thioglycolic acid, methylthioglycolic acid, thiohydroacrylic acid, thiolactic acid, and thiomalic acid; and their alkyls. esters, sulfur-containing organotin compounds such as diptyltin diyneoctyl glycolate, di-n-octyltin diisooctylthioglycolate, and the like.

The amount of these chain transfer agents used varies somewhat depending on the type of chain transfer agent and polymerization conditions such as polymerization reaction temperature, but is usually 0.001 parts by weight per 100 parts by weight of vinyl chloride monomer.
~10 parts by weight, preferably 0.01 to 1.0 parts by weight.

If the amount of this chain transfer agent used is too large, the amount of chain transfer agent remaining in the obtained graft copolymer will be large, resulting in problems in the working environment such as odor problems during the polymerization process and molding process. In addition, when the graft copolymer is used for molding, a foaming phenomenon may occur due to the residual chain transfer agent, which may cause roughness on the surface of the processed product.

Therefore, it is preferable to select a type of chain transfer agent that requires the least amount of use. Examples of chain transfer agents that meet this purpose include sulfur-containing alcohols, sulfur-containing carboxylic acids, and their esters. Examples include sulfur-containing organic compounds such as sulfur organotin compounds and trichlorethylene. Furthermore, two or more types of the above chain transfer agents can also be used in combination.

In addition, the chain transfer agent may be added to the polymerization system at the same time as water, dispersant, etc. before charging the vinyl chloride monomer to the polymerization reactor, but the chain transfer agent may be added at the same time as water and a dispersant. It is preferable to add the mixture immediately after the temperature is raised or within 2 hours after the temperature is raised because the resulting graft copolymer has a sharp particle size distribution.

Dispersants used in the graft copolymerization reaction of the present invention may be conventionally known ones, such as cellulose derivatives such as methylcellulose, ethylcellulose, flobylcellulose, hydroxyethylcellulose, and hydroxyflobilcellulose, partially saponified polyvinyl acetate, and polyacrylic acid. , synthetic polymer compounds such as maleic anhydride-vinyl ether copolymers, esters such as propylene glycol fatty acid esters, glycerin fatty acid esters, sucrose acid esters, propylene, fatty acid esters, and mixtures of two or more of these. used.

Further, the amount of the dispersant used is preferably 0.01 to 1.0 parts by weight per 100 parts by weight of the vinyl chloride monomer.

The monomer-soluble polymerization initiator used in the graft copolymerization of the present invention is not particularly limited, and polymerization initiators commonly used in the polymerization reaction of vinyl chloride monomers, for example,
-azobis-2,4-dimethylvaleronitrile, 2,2
Organic azo compounds such as '-azobis-4-methoxy-2,4-dimethylvaleronitrile, 2゜2'-7zobisisoputyronitrile, lauroyl peroxide, benzoyl peroxide, t-7'' tilperoxypivalet ), organic peroxides such as t-butyl peroxyneodecanate, di-isopropyl peroxydicarbonate, di-5ee-butyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-3-methoxybutyl Peroxydicarbonates such as peroxydicarbonate, dimethoxyinpropyl peroxydicarbonate, diethoxyethyl peroxydicarbonate, di-cyclohexyl peroxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, Examples include sulfur-containing peroxides such as acetylcyclohexylsulfonyl peroxide, acetel-2-ethylhexylsulfonyl peroxide, and mixtures of two or more of these.Also, the amount of the monomer-soluble polymerization initiator used depends on the chloride content. It is preferably 0.01 to 1.0 parts by weight per 100 parts by weight of the vinyl monomer.

Still, in the production method of the present invention, it is preferable to carry out the graft copolymerization at a polymerization reaction temperature in the range of 25 to 80° C. under stirring.

The EA-vinyl chloride-based graft copolymer obtained by the production method of the present invention is blended with various stabilizers, lubricants, etc. used in ordinary vinyl chloride-based resins, and subjected to various molding methods such as extrusion molding. It can be molded by roll molding, injection molding, blow molding, etc.

When the E i'=-vinyl chloride graft copolymer obtained by the production method of the present invention is molded using a mixture containing a stabilizer, a lubricant, etc., it has good moldability. When the cross section of the obtained molded product was observed using a transmission electron microscope, the EA phase and the vinyl chloride resin phase were uniformly compatible, and as a result, the impact resistance was greatly improved. A molded product can be obtained.

EXAMPLES The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

The following methods were used for various tests conducted in Examples and Comparative Examples.

(a) Graft efficiency Using the obtained EA-vinyl chloride graft copolymer, chlorine analysis was performed by the combustion method, and the graft copolymer obtained by the above-mentioned chlorine analysis based on the theoretical chlorine content of polyvinyl chloride. The weight of EA in the resulting gA-vinyl chloride graft copolymer was calculated by subtracting the chlorine content and calculating the remainder as EA. Further, the obtained graft copolymer was subjected to an extraction operation at 130°C for 110 hours using α,α,α-trifluorotoluene solvent, and then the solvent was removed by distillation. The weight of EA extracted by the fluorotoluene solvent was determined, and the grafting efficiency was determined using the following formula.

(b) Molding processability 1) 100 parts by weight of resin for sheet surface condition test, 3 parts by weight of tribasic lead sulfate, 1 part by weight of dibasic lead stearate, 1 part by weight of calcium stearate as a lubricant, and After 0.5 parts by weight of stearic acid was mixed in a Hensel mixer (trade name), the mixture was kneaded for 5 minutes with a 6-inch roll at a roll temperature of 170'C and a roll gap of 0.3 mm to give a thickness of 0.3 mm.
Create a decoy sheet. The surface of the obtained sheet was visually observed and evaluated according to the following criteria.

○: The surface of the sheet is smooth and glossy.

Δ: The surface of the sheet is smooth but lacks gloss.

×: The surface of the sheet is uneven and lacks gloss.

;1) Measurement of Koka type flow A part of the sheet used in the test of the surface condition of the sheet in i) was cut into square pellets of 3 mm x 3 vryyt,
Using the pellet as a sample, measurement conditions: nozzle 1φ×
10m company, temperature 190℃, preheating for 2 minutes, pressure 1001V
/crIG, the flow value of sample t2.9 was measured using a Koka type flow tester.

1;1) Brabender Plastograph gel time test resin 100 parts by weight, tribasic lead sulfate 1 part by weight, dibasic lead stearate 0.1 part by weight, lead stearate 1.5 parts by weight, calcium stearate After thoroughly mixing 0.25 parts by weight, it was used as a measurement sample.
Sample optical filler 59.653g, temperature 185°01, number of revolutions 5 using Plasticorder PLV-151 manufactured by ER Co., Ltd.
The time it takes to reach the maximum torque under the measurement conditions of Orpm (
The gelation time (minutes) was measured.

(c) After mixing 100 parts by weight of resin for impact resistance test, 3 parts by weight of tribasic lead sulfate, 1 part by weight of dibasic lead stearate, 1 part by weight of calcium stearate, and 0.5 parts by weight of steric acid,
A sheet was prepared by kneading for 5 minutes using 6-inch rolls with a roll temperature of 170°C and a roll gap of 0.3111, and the resulting sheet was kneaded at a press temperature of 180°C and a press pressure of 5 okI?
/iG, length and width 20 by press molding for 10 minutes
A flat plate with a thickness of 151 m was prepared, and a No. 3 test piece (with a notch) for the Charpy impact test was prepared from the flat plate.
A Charpy impact test was conducted in accordance with SK-7111.

(b) Average degree of polymerization (P) Measured in accordance with JIS K-6721.

Examples 1 to 4, Comparative Examples 1 to 5 Contents Into a PJ2001 stainless steel polymerization reactor, 1 liter of pure water was added.
00kg, partially saponified polyvinyl acetate 250.9, 2.2
'-azobis-2,4-dimethylvaleronitrile 251
1 melt fluorate 275.9/10 minutes, ethyl acrylate content 25 weight [% EA
As in the polymerization conditions listed in the table, in Example 1, 5.0 U,
In Example 2, 0.5 yen, in Example 3, IO+Kg, and in Example 4, 15 yen were poured into the polymerization reactor, the pressure inside the polymerization reactor was reduced, the pressure was returned to normal pressure with nitrogen gas, and nitrogen gas replacement was repeated twice. The total amount of monomers EA and vinyl chloride monomer is 50
60 kg while stirring.
The temperature was raised to a polymerization reaction temperature of .degree. C., and immediately thereafter, 15.8.9 g of 2-mercaptoethanol was added as a chain transfer agent into the polymerization reactor, and polymerization was carried out for 8 hours. After that, unreacted monomers are discharged, the graft copolymer is taken out, dried, and
A-vinyl chloride graft copolymer resin for testing was obtained.

In addition, as Comparative Examples 1 to 5, as in the polymerization conditions described in Table 1 below, Comparative Example 1 did not use a chain transfer agent and the polymerization reaction temperature was 67°C, and the other polymerization conditions were those of Example Comparative Example 2 was based on Example 1 except that no chain transfer agent was used, and Comparative Example 3 was based on Example 1 without using E A-(1), and the amount of vinyl chloride monomer charged was In Comparative Example 4, neither EA-1 nor chain transfer agent was used, the amount of vinyl chloride monomer charged was increased, and the polymerization reaction temperature was 67°C, except for the conditions where the amount was increased. ℃.Other conditions were based on Example 1, and Comparative Example 5 was EA-(1).
Polymerization, dehydration, and drying were carried out in accordance with Example 1, except that neither the resin nor the chain transfer agent was used, and the amount of vinyl chloride monomer charged was increased accordingly, to obtain test resins.

Using each test resin obtained from each experimental side and each comparison side, the average degree of polymerization was measured, the grafting efficiency was measured,
The moldability and Charpy impact strength were measured. The results are summarized in Table 1.

Examples 5 to 8 As in the polymerization conditions described in Table 1 below, Example 5 was based on Example 1 except that thioglycolic acid was used as a chain transfer agent, and Example 6 was Example 7 was based on Example 1 except that Tricrene 526.6.9 was used as the chain transfer agent, and the melt flow rate was 25 g/10.
min, 35% ethyl acrylate content EA-(
2) 5.0 kg, Example 8 is a melt flow rate)4
M/10 min, EA with ethyl acrylate content 9% by weight
-(3) Polymerization was carried out in accordance with Example 1 except that 9 was used for 5, and test resins were obtained by dehydration and drying.

Experiments The same tests as in Examples 1 to 4 were conducted using the test resins obtained on each side. The results are summarized in Table 1.

Examples 9 to 11 Example 9 followed the polymerization conditions of Example 1 except that the chain transfer agent 2-mercaptoethanol was added before heating, and Example 10 conducted the polymerization reaction using the chain transfer agent 2-mercaptoethanol. The polymerization conditions of Example 1 were followed except that the chain transfer agent 2-mercaptoethanol was added to the mouth for 1 hour after raising the temperature to the polymerization reaction temperature. is based on the polymerization conditions of Example 1.
Polymerization was carried out in accordance with the method described in 2007, followed by dehydration and drying to obtain a test resin. Using the test resins obtained on each side, the average degree of polymerization, grafting efficiency, molding processability, and Charpy impact strength were measured. The results are summarized in Table 2.

As is clear from Table 1, when graft copolymerizing a vinyl chloride monomer to EA, a chain transfer agent can be added and graft copolymerized, and as is clear from Table 2, chain transfer The timing of addition of the agent may be before the temperature rise, immediately after the temperature rise, or 1 to 2 hours after the temperature rise, but if the chain transfer agent is added immediately after the temperature rise or within 1 to 2 hours after the temperature rise, the EA- It can be seen that the particle size distribution of the vinyl chloride copolymer is sharp.

As described above, the EA-vinyl chloride copolymer obtained by the production method of the present invention can be used to provide molded products with excellent moldability and impact resistance, and can be used by extrusion molding, injection molding, It can be suitably used in various molded products by various molding methods such as calendar molding.

Written amendment to the above procedures (voluntary amendment) December 31, 1985 Commissioner of the Japan Patent Office Kuro 1) Jun Akira 1, Indication of the case 1985 Patent Application No. 248421 2, Name of the invention Manufacture of vinyl chloride-based graft copolymer Method 3: Relationship with the person making the amendment Patent applicant 3-6-32 Nakanoshima, Kita-ku, Osaka-shi, Osaka (530)
(207) Chisso Corporation representative Sadao Nogi 4, agent Shinjuku 2-8-1 Shinjuku, Shinjuku-ku, Tokyo (160) 5, subject of amendment "Claims" column and "Detailed description of the invention" Column 6, content of amendment + 11% scope of claims, is amended as shown in the attached sheet.

(2) "Return to normal pressure" on page 16, lines 6-7 of the specification is corrected to "return to normal pressure."

7. Attached document Attached to paper Claims (Full text) 1. A method for producing a vinyl chloride-based graft copolymer, the method comprising graft copolymerizing a vinyl chloride-based graft copolymer with a polymer.

(2) Ethylene-alkyl acrylate copolymer resin with ethyl acrylate content of 1 to 50% by weight and melt flow rate of 0.5 to 500.9/10 min.
A method for producing a vinyl chloride graft copolymer according to claim (1), using an ethyl acrylate copolymer resin.

(3) The amount of the ethylene-ethyl acrylate copolymer resin used is 1 to 1 based on the total amount of the copolymer resin and the vinyl chloride monomer, or the vinyl chloride monomer and the monomer copolymerizable therewith. The method for producing a vinyl chloride-based graft copolymer according to any one of claims (1) and (2), characterized in that the weight ratio is 30% by weight.

(4) Claim 11 or any one of (2) and (3) in which an organic compound having a mercapto group and a hydroxy group or a carboxy group is used as a chain transfer agent. A method for producing a vinyl chloride-based graft copolymer.

(5) The vinyl chloride-based graft copolymer according to any one of Claims (11) and (4), characterized in that the graft copolymerization is carried out at a polymerization reaction temperature of 25 to 80°C. Production method.

Claims (5)

[Claims] (1) It is characterized by graft copolymerizing a vinyl chloride monomer or a vinyl chloride monomer and a monomer copolymerizable therewith to an ethylene-alkyl acrylate copolymer resin in the presence of a chain transfer agent. A method for producing a vinyl chloride graft copolymer. (2) As the ethylene-alkyl acrylate copolymer resin, an ethylene-ethyl acrylate copolymer resin with an ethyl acrylate content of 1 to 50% by weight and a melt flow rate of 0.5 to 500 g/10 minutes is used. ) The method for producing a vinyl chloride-based graft copolymer according to item 1. (3) The amount of the ethylene-ethyl acrylate copolymer resin to be used is 1 to 1 based on the total amount of the copolymer resin and the vinyl chloride monomer, or the vinyl chloride monomer and the monomer copolymerizable therewith. 30% by weight, the method for producing a vinyl chloride-based graft copolymer according to any one of claims (1) and (2). (4) In any one of claims (1), (2), or (3), using an organic compound having a mercapto group and a hydroxy group or a carboxy group as a chain transfer agent. The method for producing the vinyl chloride graft copolymer described above. (5) The vinyl chloride graft copolymer according to claim 1 or 4, which is graft copolymerized at a polymerization reaction temperature of 25 to 80°C. manufacturing method.