JPS62246913A - Production of vinylidene chloride copolymer latex - Google Patents

Abstract

PURPOSE:To obtain a latex improved in heat stability and light discoloration resistance without detriment to the gas barrier property of its film, by emulsion- polymerizing a copolymerizable monomer mixture containing vinylidene chloride with the aid of an emulsifier and a polymerization initiator in a specified manner. CONSTITUTION:The emulsion copolymerization of 100pts.wt. monomer mixture comprising 60-94wt% vinylidene chloride and 6-40wt% monomers copolymerizable therewith is performed in the following manner. Namely, an at least 80wt% portion of the monomer mixture is fed continuously and uniformly to the polymerization system. During the continuous feeding, an at least 75wt% portion of 0.5-5.0pts.wt. nonionic emulsifier and the whole or part of a polymerization initiator is continuously and uniformly added to the polymerization system to obtain the purpose latex. The obtained latex has an MW (in terms of the solution viscosity) etasp/C of 0.035-0.075l/g (wherein etasp is a specific viscosity and C is the concentration of the solution) and a rate of emulsifier extracted from the copolymer by treatment with methanol <=40% based on the amount of the emulsifier used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a vinylidene nonachloride co-articulate latex which is a latex with excellent chemical stability and whose coating film has excellent light coloring resistance and gas barrier properties.

BACKGROUND OF THE INVENTION It is known that vinylidene chloride copolymers lose their thermal stability and photostability and become colored when metal oxides or ions thereof are present in the copolymer.

Therefore, efforts are made to avoid contamination of metals and their ions as much as possible in raw material vinylidene chloride copolymers for melt extrusion processing which require thermal stability. Further, during melt processing, a copolymer with a low melt viscosity and a small molecular weight is desirable, but a low molecular weight vinyl chloride+7dene copolymer tends to have poor thermal stability.

On the other hand, in the processing process, molten a
Anionic emulsifiers containing metal ions have conventionally been used for vinyl chloride lJ-dene copolymer latexes that are widely used and do not require relatively strict thermal stability. This is because this anionic emulsifier has excellent effects on controlling the particle size of latex and mechanical stability of latex.

However, this inferior thermal stability basically means that
- This is a major drawback, and the method of using only nonionic emulsifiers without metal ion Kanakura to improve this problem is also possible.
41-14676. However, this method has disadvantages in that the particle size of the latex cannot be controlled unless a large amount of nonionic emulsifier is used and the mechanical stability of the latex cannot be maintained. That is, when using all anionic emulsifiers, monomer 1
A highly stable latex can be obtained using an amount of 3.0 parts by weight or less based on 3.0 parts by weight of the nonionic emulsifier. 2! It is necessary to use

This large amount of emulsifier is especially important for latex T-film etc.
What is the gas barrier property of the film when it is arched and used for convenience? There is a drawback that the cost is greatly reduced and the meaning of applying the vinyl chloride + J-ten combination 1&: is lost.

Regarding the first difficult problem in using this nonionic emulsifier,
The inventors of the present invention have conducted intensive research and have completed the present invention.

That is, the present inventors have found that although the nonionic emulsifier is used in a relatively large amount, the gas barrier properties of the coating film are not improved.
We have succeeded in producing a polyvinylidene chloride copolymer which is excellent in thermal stability and light layer color stability, and which has a good chemical stability. It has been completed.

Summary of the Invention That is, the present invention provides the following features: 1. When carrying out emulsion polymerization of 100 parts by weight of a monomer mixture consisting of 60 to 94 oz. More than 80% of the mixture is added continuously and uniformly, and during the continuous addition period, 0.5 to 5% of the nonionic emulsifier is added. 75 of oi fubu. ! If all or a part of the polymerization initiator is added continuously and uniformly in an amount equal to or more than
C-0,035 to 0.0751/9 ('/a is specific viscosity, C: d liquid donation degree), and the amount of emulsifier extracted from the copolymer with methanol is 40% or less of the emulsifier used. A method for producing vinylidene co-electric latex.

2. After carrying out emulsion polymerization in advance using less than 201 φ of the monomer mixture, less than 25 M of the nonionic emulsifier, and less than 30 ml of the polymerization initiator, the remaining mixture, the nonionic emulsifier, and the polymerization were Polymerization by adding initiator completely continuously and uniformly? A method for producing a vinylidene chloride copolymer latex according to claim 1.

It is related to.

The present invention involves continuously and uniformly adding a nonionic emulsifier and a polymerization initiator during the continuous addition period of the monomer mixture during emulsion polymerization of a monomer mixture containing vinyl chloride and +7Den7 as main components. According to a characteristic emulsion polymerization method of the present invention, a latex containing a vinylidene chloride copolymer having a specific molecular weight (ηs p/C) and a small amount of emulsifier extraction can be produced.

By the method described above, a chemically and mechanically stable latex can be obtained using a relatively small amount of nonionic emulsifier, and the copolymer coating film obtained by applying this latex 1c has good light resistance and gas barrier properties. Rich in sex, tobacco,
It is extremely useful for packaging good products, etc.

DETAILED DESCRIPTION OF THE INVENTION The monomer mixture used in the present invention contains vinylidene chloride in an amount of 60 to 94 weights, preferably 75 to 93 weights, and contains a monomer copolymerizable with vinylidene chloride in an amount of 6 to 94 weights. 40t
It consists of Jlchi, preferably 7 to 25[tchi]. If the amount of vinylidene chloride is less than 60 FJts, the resulting copolymer will have almost no crystallinity and will have poor gas barrier properties. On the other hand, if the weight is more than 94%, the copolymer is in the form of a latex and crystallizes in a short period of time, which is disadvantageous because it cannot be used in applications where latex is used to form a film. Monomers copolymerizable with vinylidene chloride include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, acrylic ff-2-ethylhexyl, octyl acrylate, methyl methacrylate, ethyl methacrylate, and acrylic acid. One or more selected from glycidyl, methacrylic acid, glycidyl, acrylonitrile, methacrylonitrile, vinyl chloride, vinyl acetate, acrylic acid, methacrylic acid, itaconic acid, etc. can be preferably used.

The nonionic emulsifier used in polymerization is the total amount of monomers used.
0.5 to 5.00 parts by weight. Oin part, preferably 1.0-3.0tjt part. The amount of emulsifier depends on the ratio of water and monomers used during polymerization, but it is recommended to use as little as possible within the range that maintains the stability of the latex during polymerization. In other words, when the solids concentration of the latex is relatively small (30% or less), full stability can be maintained with a small amount of emulsifier, but stability is compromised if the emulsifier is less than 0.53 parts.On the other hand, nonionic emulsifiers If it exceeds 5.0 parts by weight, the gas barrier properties will deteriorate.Preferably, LO~3.9
Parts by weight range.

Examples of nonionic emulsifiers that can be used include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, holoxyethylene fatty acid esters, and polyoxyethylene sorbitan fatty acid esters. As the polymerization initiator, water-soluble inorganic peroxides, organic peroxides, and organic peroxides that are even slightly soluble in water can be used, and in some cases, these and a reducing agent may be used. It can also be used as a redox initiator in combination with As the inorganic peroxide, potassium 1111 sulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, etc. can be used. Examples of organic peroxides include t-butylhydrono-oxide, succinic acid), t-butylperoxymaleic acid, and cumene hydroperoxide 9.
, etc. can be used.

Furthermore, water-soluble azo compounds such as 23/-azobis(2-amidenopropane hydrochloride) can also be used.Reducing agents to be used in combination with these peracids include sodium bisulfite, Rongalite salt, oxalic acid, and maleic acid. , hydroquinone, paraoxybenzoic acid, thiourea, or ascorbic acid.

The amount of the polymerization initiator to be used varies depending on the molecular weight of the desired copolymer, etc., but is usually preferably 0.02 to α2 parts by weight per 100 parts by weight of the monomer mixture. It is also necessary that all or at least a portion of the polymerization initiator be added continuously during the period that the monomer mixture is continuously added. The amount to be added continuously is preferably 10 g per total initiator chilled mass.

Next, we will explain the specific method of emulsion polymerization of the present invention.7 In the present invention, a total of 1 liter of the above monomer mixture, nonionic emulsifier, and initiator is placed in a pressure-resistant container into which deionized water is charged.
(2) A portion of the monomer mixture, nonionic emulsifier, and polymerization initiator may be added continuously and uniformly from the start of fem polymerization, or after polymerization has been carried out to some extent, the remaining monomers may be added. The polymer mixture, nonionic emulsifier, and heavy initiator may all be added continuously and uniformly.

It is preferable to cool the nonionic emulsifier and polymerization initiator in the form of an aqueous solution.In the case of (2) above, a small amount of monomer mixture,
Nonionic emulsifier, initiator'th in water for 1 hour beforehand〃a
Emulsification is carried out on M8- (so-called 1 cup of seeds),
The Jl is 20Mm% of the total amount of single and thermal mixtures.
It is preferred that the nonionic emulsifier is less than 25% by weight and the polymerization initiator is less than 30% by weight. In other words, it is necessary that at least 75% by weight of the emulsifier mixture and a part of the polymerization initiator are continuously cooled while at least 80% by weight of the monomer mixture is continuously added. It is. The composition of the monomer mixture and the type of nonionic emulsifier during continuous addition may always be the same or different. In the case of (2), the composition of the monomer mixture and the type and composition of the emulsifier during pre-polymerization may be the same as or different from those during continuous addition. (
Between 1) and (2), (2) is preferable because the number of polymer particles is constant and the particle size can be easily controlled.

In emulsion polymerization, if the number of particles is constant, the polymerization rate is proportional to the monomer concentration in the polymer particles, and the average degree of polymerization (molecular weight) is proportional to the monomer concentration in the polymer particles. It is inversely proportional to the radical penetration rate. Therefore, the monomer concentration in polymer particles and the rate of radical penetration into the particles are important factors governing the polymerization rate, average degree of polymerization, and degree of polymerization distribution in emulsion polymerization.

In the present invention, a nonionic emulsifier and a polymerization initiator are simultaneously and continuously added and polymerized during the continuous σ of the monomer mixture during the mouth opening, thereby uniformizing the polymerization rate, average degree of polymerization, and degree of polymerization distribution to achieve the desired purpose. This is what we achieved.

For example, if the entire amount or 20 weight or more of the monomer mixture is added at once during polymerization, the present invention not only cannot maintain the stability of the latex because it does not contain an anionic emulsifier and the amounts of emulsifier and initiator are small. Polymerization reaction is difficult to proceed. Continuous addition of monomers is not only effective in controlling the total monomer concentration in polymer particles, but also in copolymerization between monomers with widely different copolymerization reaction ratios. It is also effective for obtaining a comonomer having a composition.

In addition, if the entire Ik or 25-weight emulsifier 11 is added at the beginning, or if the remaining amount is added during the polymerization, not only will the polymerization be delayed, but the chemical stability of the latex will deteriorate, and as will be discussed later. The presence of a large amount of emulsifier increases the number of polymer particles, which ultimately inhibits the chemical stability of VC, but on the other hand, temporarily It is thought that it is densely adsorbed on the surface of polymer particles, decreasing the monomer penetration rate and radical penetration rate, and having an adverse effect on the polymerization rate and degree of polymerization. Therefore, during polymerization, it is extremely important to ensure that the amount of emulsifier adsorbed to latex particles is always uniform, as well as to uniformly add monomers and initiators, as well as to control the polymerization rate and degree of polymerization. As a guideline for uniform addition of the emulsifier, it is desirable to maintain the surface tension of the latex constant.

On the other hand, if the entire amount or more than half of the polymerization initiator is added at once at the beginning of polymerization, the degree of polymerization of the copolymer formed at the initial stage of polymerization will be small, and the thermal stability of the copolymer will not only deteriorate. However, the problem arises that the polymerization reaction is delayed in the latter half of the polymerization. In addition, it is a preferable method to make sure that the reducing agent is present in the entire polymerization system so that the added initiator immediately becomes radicals and the radical concentration is always constant during the polymerization, in order to obtain a uniform polymerization rate and degree of polymerization. It is. Furthermore, after the continuous addition of the monomer mixture, 1J of the initiator can be added to complete the polymerization.

In this way, in the present invention, the monomer mixture, the nonionic emulsifier,
It is an essential condition that the initiator be added simultaneously, continuously and uniformly to the heavy-containing system. Here, "uniformly added" refers to substantially constant addition within the same time period, that is, addition and disappearance at the same fermentation rate.

The degree of polymerization or molecule i of the copolymer obtained in the present invention is expressed as a solution viscosity and is η6p/C-α035 to 0.0751.
/9 (ηsp: specific viscosity 1C: bath liquid concentration), more preferably α04 to 0.07fl/9.

If it is less than 0.035, the thermal stability and light coloring resistance will be extremely poor, while if it exceeds α075'i, it will be difficult to melt and the heat sealability will deteriorate. In particular, if the contact time with the hot plate during heat sealing is less than α5 seconds, the heat sealing properties will deteriorate due to adhesion.

In the present invention, the above-mentioned monomer mixture, initiator, and nonionic emulsifier are continuously added tV so that the degree of polymerization falls within this range.
Adjust. Additionally, the polymerization temperature can also be determined accordingly. However, generally the polymerization temperature is preferably 30 to 70°C.
The solution viscosity is calculated by measuring the 49/ffi bath solution viscosity of cyclohexanone at 30'C.

Furthermore, in the present invention, by simultaneously and continuously adding a monomer mixture, a nonionic emulsifier, and a polymerization initiator to the polymerization system,
It was surprisingly found that most of the nonionic emulsifiers existed in such a state that they could not be extracted from the copolymer by methanol extraction, and the methanol extraction rate was only 40% or less of the total emulsifiers used. . As a result, the chemical stability of the latex of the present invention is extremely superior to that of conventional latexes using only nonionic emulsifiers. Although the detailed reasons for this finding confirmed by the present inventors will have to wait for future research, the simultaneous and continuous addition of the above-mentioned monomer, initiator, and emulsifier to the foil, especially the initiator It is presumed that the nonionic emulsifier is grafted onto the copolymer because radicals are constantly generated in water.

Due to the existence of such a nonionic emulsifier, a stable latex can be obtained with a relatively small amount of nonionic emulsifier even though it does not contain an anionic emulsifier, and since it does not contain an anionic emulsifier, the thermal stability of the copolymer is It is considered that the gas barrier properties have reached an unprecedented level of performance.

Now, a latex is obtained as described above, but the optimum particle size of the latex is in the range of 800 to 2000A, and such a particle system has a total appropriate amount of emulsifier, initiator, and monomer at the initial stage of polymerization. It can be obtained by adjusting.

The latex of the present invention can be used with the addition of silica, wax, pigments, and other calorific agents, cationic surfactants as antistatic agents, and alcohols as surface tension adjusters or antifoaming agents. Moreover, it can be coated on paper, plastic film, etc. using a normal coating method.

The usefulness of the present invention will be explained below using Examples and Comparative Examples. Chi and part below indicate the weight part and the amount part, respectively. First, the evaluation test method will be described.

(1) Chemical stability of latex Latex with a solid content concentration of 50%, methanol at 20°C, and a cationic surfactant solution with a concentration of 10% (cationic surfactant: manufactured by Lion Akzo Co., Ltd., Esocard C-
12) Add 1-2 drops to each of the (i!
I tested it to see if it would coagulate (coagulate), and if it did not coagulate and had a milky white color, I would consider it next.

(2) Methanol extraction rate of emulsifier A latex with a solid content concentration of 50% is coated on a biaxially stretched polypropylene film (abbreviated as OPP) with a solid content thickness of 5 μm.
Coat the film to a thickness of m and dry it in a room at 20°C to form a film.

After drying, only the coating film was peeled off with cellophane adhesive tape, and the coating film of about 109 was cut into strips, and extracted with methanol solvent using a Soxhlet extractor for 50 hours. In addition, the extracted TV was measured once in the 40 o'clock time period, and it was confirmed that the weight had become constant at 50 hours. However, 50
If the constant weight was not reached even after hours, further measurement was carried out at about 10 o'clock, and extraction was continued until the constant weight was reached. The methanol extraction rate is expressed as the amount of extracted emulsifier relative to the total amount of emulsifier used.

(3) After freezing and coagulating the molecular weight latex, it was washed with methanol and dried in a vacuum dryer to obtain a powder. This powder sample was dissolved in cyclohexanone to a concentration of 4971, and heated to 30°C.
The total viscosity of the solution was measured, and η81y/C was calculated.

(4) Urethane resin adhesive "Takelac A-axOJ and rTakene-" A-3J (manufactured by Narita Pharmaceutical Co., Ltd. ) at a ratio of 15=1, coated to give a solid content of 0.39/rrL2, dried at 80°C for 30 seconds, and then immediately coated with latex with a solid content concentration of 40% [ Silica, powder, thyroid"2
44 (manufactured by Fuji Techson) K resin 100! j0.2 per copy:! The solid content of [fik part added] is 5.
Coat the ACC screen so that it is 09/m" and
Dry for 0 seconds. After drying, it was left at 40°C for 48 hours, and then heated at 20'C and 90% fI for 20 hours. MDCON was applied to this sample at 20°C and 99% RH.
It was measured using a 0X-TRAN100 type tester.

(5) Resistance to pre-coloring (a parallel relationship with thermal stability has been recognized, so we measured the coloring property of light emitted as a guideline for thermal stability). The latex was applied as a solid content in ions/m2 and dried at 80°C for 30 seconds. then 40
It was left at ℃ for 48 hours. Thereafter, it is cut into strips and stacked with the coated side facing up. During this period of 10:00 a.m. to 3:00 p.m. when the weather is completely clear, the σ-shaped sample is kept in a bottleneck until the predetermined sowing time is reached. Coated surface of sample with 1210 pieces of color fading? In the table, color difference meter (1i, Tori'-Iro Co., Ltd., TCA-Ko fM) Terror+lI, Yh:
LLOW ENGRJDEX -c' display position.

Example 1 Deionized water 80 parts Potassium persulfate α0 15 parts Sodium sulfite aqueous solution 0. O1 club preparation,
After sufficiently purging with nitrogen gas, 9.0 parts of vinyl chloride/0.7 parts of methyl methacrylate and 0.3 parts of methyl acrylate were rapidly added using a pump, and after stirring at 45°C for 3 hours (seed polymerization). , 1 ml aqueous solution of sodium bisulfite 6.
0 parts of the mixture was added to the mixture at a rate of 10 parts per hour. At the same time as the continuous addition of the above monomer mixture was started, the following aqueous solution was prepared and added continuously at a rate of 1 part per hour.

ZV, t-+diethylene nonylphenol ether
i, s parts (Emulgen 930) Potassium persulfate 0.01 parts Deionized water 7.5 parts Single substance mixture, emulsifier, polymerization initiator 1 hour after the completion of 48 mouths of the total amount of water bath solution, potassium persulfate o, oi parts Sodium bisulfite o, otg was added to a mixture of 4.0 parts of deionized water, and stirring was continued for an additional 3 hours at 45°C to obtain a latex. The results are shown in the first N.

Example 2 The same method as in Example 1 except that the amount of deionized water initially charged was 75 parts, and the amounts of the emulsifier and polymerization initiator to be added continuously and their total addition ratios were changed as follows. Polymerized with friends.

To a mixture of 0.02 parts of potassium persulfate and 14.0 parts of deionized water, 71 Fl were added continuously at a rate of 2 parts per hour.

Example 3 Example 1 except that the monomer composition was changed as follows.
Polymerization was performed in the same manner as .

Seed polymerization monomer Vinylidene chloride 9.0 parts Methyl acrylate 1.0 parts Continuously interfaced monomer Vinylidene chloride 81 parts Glycidyl methacrylate 3. os Methyl acrylate 6.0 parts Example 4 75 parts of deionized water and 0.1 part of Rongalit's salt were placed in a glass-lined autoclave equipped with a stirrer, and after sufficiently purging with nitrogen gas, 3.0 g of polyoxyethylene nonylphenol ether ( Kako Atlas Co., Ltd. Emaldan 935-t-butylhydronoxide
0.01 part deionized water
18 parts mixture? ! - Continuous addition was started at a rate of 2 parts per hour. After 30 minutes, the following monomer mixture was added at a rate of 10 parts per hour.

Vinylidene chloride 90 parts Methyl methacrylate 4 parts Methacrylonitrile 3 parts Methyl acrylate 3 parts One hour after completion of the above monomer mixture 'jIA711], 90 parts of t-butylhide (peroxy)' 0.02 parts Deionized 4.0 S of water was added, and the mixture was stirred at 45°C for 3 hours. The results of evaluating the properties of the latex and the physical properties of the copolymer in Examples 1 to 4 are shown in Table 1. Comparative Example 1 Stirring in a glass-lined autoclave, 80 parts of deionized water, 80 parts of perbiased potassium silica, 0.0151 fox sulfite. After charging 0.011U of sodium hydrate and replacing it sufficiently with nitrogen gas, vinylidene chloride was added.
9.0 parts Methyl methacrylate 0.7 parts Methyl acrylate
0.3 parts of silkworm eggs were added rapidly using a pump, and after stirring at 45°C for 3 hours (seed polymerization), 6.0 parts of a 1-part aqueous solution of sodium bisulfite were added to the silkworm eggs, and then 82 parts of vinylidene chloride and methyl methacrylate were added. A mixture of 5.5 parts acrylonitrile and 2.5 parts was added to the silkworm eggs at a rate of 10 parts per hour, and the deionized water containing 1 part of potassium persulfate was continuously added to the mixture at a rate of 1 part per hour. Added Fi. One hour after the monomer mixture and the polymerization initiator water bath had been mixed, the same polymerization initiator as in the example was cooled and stirred at 45° C. for 3 hours to obtain a latex. Even when all of the monomers were added continuously, no polymerization occurred in @Toru, and an exothermic peak of polymerization was observed 3 hours after the start of monomer addition. The chemical stability of the obtained latex was unstable with respect to methanol, and the emulsifier extraction rate was as high as 93%. On the other hand, the molecular weight of the copolymer is 0
．． Although it was large at 068fi/9 and the light color fastness was poor,
Compared to Example 1, the gas barrier properties were inferior.

Comparative Example 2 1.5 parts of polyoxyethylene phenol ether in Example 1, 0.01 part of potassium persulfate, 7 parts of deionized water
1.5 parts of polyoxyethylene phenol ether and 7.5 L of water were continuously added in the same manner as in Example 1, and 0.02 parts of potassium persulfate and 2.0 parts of water were added.
Polymerization was carried out in the same manner as in Example 1, except that S was added to the emulsifier at once at the beginning of the 4-hour period and after 4 hours.The resulting latex was unstable to methanol and friend. The emulsifier extraction rate was as high as 78%, which was higher than in Example 1 due to the gas barrier properties of the copolymer.

Comparative Example 3 1.5 parts of polyoxyphenol ether, 0 potassium persulfate, 7.5 parts of Olg-deionized water (5.5 parts of l-polyoxyethylene phenol ether, persulfate) added continuously to Example 3. Polymerization was carried out in the same manner as in Example 3, except for using 0.02 part of potassium and 7.5 m of deionized water.The chemical stability of the latex was excellent, but the gas barrier properties of the copolymer were poor. The results of Comparative Examples 1 to 3 are summarized in Table 1.

Procedural amendment written on July 1, 1988 1, Indication of the case Patent Application No. 88320 of 1988 2, Name of the invention Process for producing vinylidene chloride copolymer latex 3, Person making the amendment Relationship to the case ° Patent Applicant name: Kureha Chemical Industry Co., Ltd. Kasumigaseki Building Post Office I*i No. 49 8. Contents of amendment (11. Item a of "Scope of special IFFM request" in the specification is amended as shown in the attached sheet.

(2) The "Detailed Description of the Invention" column of the specification shall be amended as follows.

1) On page 4, lines 10-11 of the specification, “complete” is replaced with “
It will be completed,” he corrected.

2) Delete "relatively large amount" from page 4, line 16 of the same book.

6) "Anionic emulsifier" in page 11, line 20 to page 12, line 1, page 15, line 16, and line 15 of the same book is corrected to "anionic emulsifier."

4) In the same book, page m12, line 5, "copolymerization reaction ratio" is corrected to "copolymerization reactivity ratio."

5) In the same book, page 13, line 11, "polymerization rate and degree of polymerization" is corrected to "polymerization rate and degree of polymerization".

6) On page 19, line 14 of the same book, "polyoxyethylene nonyl ether" was amended to "polyoxyethylene nonylphenol ether."

7) In the same book, page 24, lines 19-20, "polyoxyethylene phenol ether" is corrected to "polyoxyethylene nonylphenol ether J."

8) The same book, page 25, lines 1 and 2, “Polyoxyethylene phenol ether J wor, tr IJ oxyethylene nonyl phenol ether 1.! [Correct.

9) On page 25, lines 11 and 12 of the same 'iM, "polyoxyphenol ether" is corrected to "polyoxyethylene nonylphenol ether."

10) Ibid., page 25, lines 16-14, "polyoxyethylene phenol ether" is defined as [polyoxyethylene nonylphenol ether 1. ! [Correct.

11) Replace all “nonionic emulsifiers” in the sections shown below with “
"Nonionic emulsifier".

Claim 1, Vinyl chloride IJden 60-94% by weight, Vinyl chloride 17
When emulsion polymerizing 100 parts by weight of a monomer mixture consisting of 6 to 40% by weight of monomers that can be copolymerized, 80% by weight or more of the monomer mixture is added continuously and uniformly; The resulting copolymer solution is characterized by continuously and uniformly adding at least 75 parts of a nonionic emulsifier (0.5 to 5.0 parts by weight) and all or part of a polymerization initiator during the period. The molecular weight expressed in viscosity is ηsp/C=
0.055-0.0751/lηsp: Specific viscosity, C:
A method for producing a vinylidene chloride copolymer latex in which the extraction rate of the emulsifier from the copolymer with methanol is 40% or less of the emulsifier used.

2 After carrying out emulsion polymerization in advance using less than 20% by weight of the monomer mixture, less than 25% by weight of the nonionic emulsifier, and less than 30% by weight of the polymerization initiator, the remaining monomer mixture and the nonionic emulsifier The method for producing vinylidene chloride copolymer latex according to claim 1, wherein the polymerization is continued by continuously and uniformly adding a polymerization initiator.

Claims (1)

[Scope of Claims] 1. When emulsion polymerizing 100 parts by weight of a monomer mixture consisting of 60 to 94% by weight of vinylidene chloride and 6 to 40% by weight of a vinylidene chloride copolymerizable monomer, 80 parts by weight of the monomer mixture is 75% by weight or more of the nonionic emulsifier is added continuously and uniformly during the continuous addition period.
It is characterized in that at least % by weight and all or a part of the polymerization initiator are added continuously and uniformly, and the resulting copolymer has a molecular weight expressed as a solution viscosity of η_s_p/C=0.
035 to 0.075 l/g (η_s_p: specific viscosity, C:
1. A method for producing a vinylidene chloride copolymer latex in which the extraction rate of the emulsifier from the copolymer with methanol is 40% or less of the emulsifier used. 2 After carrying out emulsion polymerization in advance using less than 20% by weight of the monomer mixture, less than 25% by weight of the nonionic emulsifier, and less than 30% by weight of the polymerization initiator, the remaining monomer mixture, the nonionic emulsifier, and the polymerization The method for producing vinylidene chloride copolymer latex according to claim 1, wherein the polymerization is continued by continuously and uniformly adding an initiator.