JPS6323947A - Production of polyvinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To obtain a polyvinyl chloride resin composition of improved processability, by mixing a specified three-stage polymer with a polyvinyl chloride resin-containing suspension polymerization solution, coprecipitating these polymers by the addition of a coagulant and separating the coprecipitate. CONSTITUTION:The following components I and II are mixed together in liquid form and a coagulant is added to the resulting mixture to coprecipitate components I and II. This coprecipitate is separated to obtain the purpose resin composition. Said component (I) is a suspension polymerization solution containing PVC containing at least 80wt%, based on the structural units, of vinyl chloride units. Said component (II) is an emulsion polymer containing a three-state polymer obtained by polymerizing MMA or its copolymerizable mixture (C) in the presence of a two-stage polymer comprising a polymer consisting of components A and B, obtained by polymerizing a mixture (B) of 1-18C alkyl (meth)acrylates in the presence of a (co)polymer containing at least 80wt%, based on the structural units, MMA units (A).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a polyvinyl chloride resin composition. The present invention relates to a method for producing an excellent polyvinyl chloride resin composition.

[Prior Art and Problems to be Solved by the Invention] Polyvinyl chloride resins have good chemical and physical properties and are therefore widely used in various fields. However, this polyvinyl chloride resin has poor processability, so it is difficult to apply it depending on the purpose. In other words, it has a high melt viscosity and poor fluidity, and furthermore, the processing temperature and thermal decomposition temperature are close to each other, so the temperature range in which good molding can be performed is narrow, and the gelation rate is slow. In a roll kneading operation or the like, it is difficult to quickly transform a powder into a uniform melt, and furthermore, when the melt is molded, the surface condition is often poor.

A commonly used method to solve these problems is to add a plasticizer to polyvinyl chloride resin, but this method not only causes the plasticizer to volatilize, but also causes a decrease in mechanical properties. However, the limitations on the use of hard polyvinyl chloride resins have not yet been completely resolved.

On the other hand, during the molding process of polyvinyl chloride resin, it increases the gelation rate of the resin, reduces the adhesion to the metal surface of the molding machine, improves productivity, smoothes the surface of the molded product, and allows continuous use for a long time. A copolymer that is compatible with polyvinyl chloride resin is used as a processing aid for the purpose of improving processability, giving the molded product a gloss that does not change even after molding, and making it possible to deep draw the molded product. It is being considered as For this purpose, the main processing aid currently used on the market is a copolymer containing methyl methacrylate as a main component.

A polyvinyl chloride resin mixed with these copolymers has a great effect of accelerating the gelation rate, and has greatly improved secondary processability, such as increased tensile elongation at high temperatures. However, on the other hand, there are problems that reduce the commercial value of the molded product, such as lack of gloss in the extruded film and the occurrence of ungelled matter (also called fish eyes). In addition, the above-mentioned methyl methacrylate copolymer has high adhesion to metal surfaces due to its woody nature, and has a high melt viscosity. A problem directly connected to productivity has been found in which resistance (resistance) increases significantly.

In order to improve these problems, the use of various lubricants in combination with processing aids is being considered, but the amount used is limited in order to maintain the physical properties of the vinyl chloride resin composition at a certain level. Therefore, it is not possible to combine an effective amount,
Therefore, problems such as lack of sustainability of lubricity cannot be solved, and the use of lubricants can cause problems such as adhesion of lubricants to molds, etc. (also called plate-out) during bloom processing on the surface of molded products. Since new problems arise, this cannot be a general solution.

As a composition that solves the above problems all at once, it maintains the transparency of polyvinyl chloride resin, improves its elongation at high temperatures and secondary processability such as deep drawing, and can be rolled during calendering. Compositions have also been developed that have extremely excellent long-term lubricity properties such as releasability from surfaces.
It has achieved considerable effects (for example, Japanese Patent Application Laid-Open No. 1983-1996)
However, on the other hand, from the viewpoint of improving productivity and saving energy, processing aids that gel more quickly and have long-lasting lubricity during processing of polyvinyl chloride resin are needed. However, from these points of view, the above composition has its limits. Furthermore, depending on the composition, an increase in deposits on molds, etc. (plate-out) may be observed during molding, and it cannot be said that market demands are fully met.

Therefore, the present invention aims to make it possible to apply it to a wider range of fields by improving the processability of polyvinyl chloride resin compositions, which has hitherto been insufficient.

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors have completed the present invention by focusing on the following points. .

That is, (1) the composition obtained by mixing the components (1) and (II) described below constituting the composition according to the present invention in a liquid state and co-precipitating them, compared to when they are mixed in a powder state. (2) The component (II) constituting the composition according to the present invention is a methyl methacrylate-based component with low fluidity and hard high molecular weight [(A) to be described later. A mixture of a low molecular weight methacrylic ester with a large lubricating effect and an acrylic ester [component (B)]
A latex containing a three-stage polymer obtained by three-stage polymerization in which a methyl methacrylate monomer [component (C)] that is highly compatible with polyvinyl chloride resin is polymerized around it in an extremely dense manner. (11) Due to the mutual effect of the components constituting the three-stage polymer, especially the methacrylic ester and the acrylic ester of component (B), the composition has excellent lubricity and secondary processability. To give, to be able to.

The method for producing a vinyl chloride resin composition of the present invention includes (I) a suspension polymerization solution containing a polyvinyl chloride resin in which at least 80% by weight of its constituent units are vinyl chloride units; 100 parts by weight of polyvinyl chloride resin; (TI) (A) a polymer or copolymer in which at least 80% by weight of the constituent units are methyl methacrylate units; (B) In the presence of 10 to 45 parts by weight of a solution obtained by dissolving 0.1 g of 1004 in chloroform, the reduced viscosity at 25°C (ηsp/c, hereinafter the same) is 2 or more; 40 to 70 parts by weight of a mixture of 30 to 70% by weight of alkyl methacrylate having an alkyl group having 1 to 18 carbon atoms and 70 to 30% by weight of alkyl acrylate; ηsp of component (B) alone In the presence of a two-stage polymer consisting of a polymer having component (A) and component (B) as constituent units obtained by polymerization under conditions such that /c is 1 or less, (C) methyl methacrylate 50 5 to 40 parts by weight of methyl methacrylate or a mixture containing it, consisting of 50 to 100% by weight of monomers copolymerizable with the methyl methacrylate [provided that (A), (B) and (C ) Total amount of components 1 ± 100 parts by weight] ; An emulsion polymer latex containing a three-stage polymer obtained by polymerizing under conditions such that η sp / c of component (C) alone becomes 2 or more. After mixing 0.1 to 25 parts by weight of M as a three-stage polymer contained in the latex, components (1) and (II) are coprecipitated by adding a coagulant to the mixture. The polyvinyl chloride resin contained in the suspension polymerization solution of component (I) constituting the composition according to the present invention is a homopolymer of vinyl chloride units or a vinyl chloride unit. and other monomer components, or a mixture thereof. When a copolymer is used as the polyvinyl chloride resin, it is necessary that at least 80% by weight of its constituent units be vinyl chloride units. Other monomer components constituting this copolymer are not particularly limited as long as they do not impair the purpose of the present invention, but include, for example, vinyl acetate, ethylene, propylene, methyl methacrylate, etc. can be used in combination of one or more types. Moreover, when using the above mixture, the mixing ratio of the vinyl chloride polymer and the copolymer is not particularly limited.

A suspension polymerization solution made of such polyvinyl chloride resin is
It can be obtained by suspension polymerization of monomers such as vinyl chloride using general oil-soluble catalysts and dispersants.

The emulsion polymer latex of component (II) constituting the composition according to the present invention is produced in the presence of component (A) (B) and (C).
3 whose constituent units are component (A), components (B) and (C) obtained by polymerizing components (A) and (B) and (C) in this order in the same system.
It contains a step polymer.

Component (A) constituting such a three-stage polymer is polymethyl methacrylate or a copolymer in which at least 80% by weight is methyl methacrylate, but there are no particular restrictions on the copolymer of methyl methacrylate. For example, one or more of aromatic vinyl, unsaturated nitrile, vinyl ester, acrylic ester, or methacrylic ester other than methyl methacrylate. However, if the amount used exceeds 20% by weight, the characteristics of the present invention will be impaired, which is not preferable. Furthermore, it is also possible to use polyfunctional monomers such as divinylbenzene and allyl methacrylate. but,
In this case, the amount used is preferably 2% by weight or less.

One of the characteristics of the present invention is that such component (A) has a large molecular weight, and specifically, the η of component (A)
A molecular weight that exhibits sp/c of 2 or more is necessary in order to exhibit excellent secondary processability and sustained lubricity. If ηsp/c is less than 2, not only will no effect be observed on the processability of polymethyl methacrylate or methyl methacrylate copolymer, but also the additive effect with component (B) will be small and the sustainability of lubricity will be reduced. come.

The content of component (A) in 100 parts by weight of the three-stage polymer is 10 to 45 parts by weight, preferably 20 to 40 parts by weight. If it exceeds 45 parts by weight, lubricity will be impaired, and if it is less than 10 parts by weight, secondary processability other than lubricity will be impaired, and the durability of lubricity will also deteriorate.

Component (B), which is a structural unit of the polymer constituting the intermediate layer of the three-stage polymer, is composed of a mixture of an alkyl methacrylate ester and an alkyl acrylate ester, both of which have an alkyl group having 1 to 18 carbon atoms.

As the acrylic acid alkyl ester of component (B), for example, ethyl acrylate, butyl acrylate, inbutyl acrylate, 2-ethylhexyl acrylate, etc. can be used, and as the methacrylic acid alkyl ester,
For example, methyl methacrylate, ethyl methacrylate,
Although butyl methacrylate and the like can be used, monomers having a particularly low glass transition temperature, such as butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, etc., are particularly preferred as the acrylic acid alkyl ester in order to achieve the object of the present invention. In addition, in order to exhibit this effect, it is necessary that the methacrylic alkyl ester and the acrylic alkyl ester in component (B) take the form of random copolymerization, and the acrylic alkyl ester must be mixed with the methacrylic alkyl ester. It is undesirable to have a bonding mode such as grafting or vice versa, i.e., if there are block bonds such as butyl acrylate in the product, it is difficult to mix the final product with polyvinyl chloride resin. The composition will lose all transparency. The mixing ratio of the methacrylic acid alkyl ester and the acrylic acid alkyl ester as component (B) is 30 to 70% by weight of the methacrylic acid alkyl ester and 70 to 30% by weight of the acrylic acid alkyl ester. If the acrylic acid alkyl ester exceeds 70% by weight, the gelation behavior of the final product will be extremely slow, so the effect on lubricity such as mold releasability from metal surfaces and extrusion rate will be good. , the physical properties such as surface properties are poor.

The content of the polymer having component (B) as a structural unit in 10 parts by weight of the three-stage polymer is 40 to 70 parts by weight, preferably 50 to 70 parts by weight.
It is 60 parts by weight. If it is less than 40 parts by weight, lubricity will be impaired, and if it exceeds 70 parts by weight, secondary processability and lubricity will be lost. The major feature of component (B) is that the molecular weight after polymerization is kept extremely low.
It is necessary to make sp/c 1 or less in order to obtain excellent sustainability of lubricity, and preferably ηsp/c is 0.8 to 0.8.
It is 0.2. When ηsp/c exceeds 1, the lubricant effect characteristic of component (B) is lost, and ultimately the three-stage polymer no longer exhibits excellent lubricity.

Component (C), which is a structural unit of the polymer constituting the outermost layer of the three-stage polymer, is a mixture consisting of methyl methacrylate and a monomer copolymerizable with the methyl methacrylate. The content of methyl methacrylate in this mixture is 5
0-100% by weight, other monomer components are 50-0%
% by weight, but in order to effectively impart excellent secondary processability to the resulting composition, it is preferable to use methyl methacrylate alone, and the polymer containing component (C) as a constituent unit is From the viewpoint of secondary workability, it is necessary that η3p/c be 2 or more. As the monomer copolymerizable with methyl methacrylate, one or more of the monomers described in the section of component (A) above can be used.

The content of the polymer having component (C) as a structural unit in 100 parts by weight of the three-stage polymer is 5 to 40 parts by weight, preferably 10 to 3 parts by weight.
It is 0 parts by weight. If it is less than 5 parts by weight, excellent secondary processability cannot be fully exhibited, but secondary agglomeration tends to occur in post-processes such as coprecipitation, dehydration, and drying, resulting in problems in terms of productivity. Moreover, if it exceeds 40 parts by weight, the long-term sustainability of slipperiness will be lost.

The three-stage polymer that is a component of the composition according to the present invention can be produced by the following method.

First, a first stage emulsion polymerization is performed using the monomers constituting component (A) in the presence of a suitable medium, emulsifier, and polymerization initiator to obtain a polymer as component (A). The medium used in this emulsion polymerization is usually water; the emulsifier is
A known 7-ionic surfactant or nonionic surfactant may be used; and as the polymerization initiator, a water-soluble or oil-soluble single type or a redox type can be used. Polymerization conditions such as polymerization temperature and time are ηsp/c
can be appropriately adjusted so that the value of ηsp/c (ie, molecular weight) is 2 or more, and a chain transfer agent is added to adjust this ηsp/c (ie, molecular weight).

Next, after adding component (B) to this reaction system, the second
Perform stage polymerization. This second stage polymerization.

According to the first stage polymerization, the second stage polymerization is carried out under conditions such that ηsp/c of the homopolymer containing the Mir& units of the component (B) is 1 or less. A layer of a polymer having component (B) as a constituent unit can be formed to cover the outer surface of the composite.

Next, after adding component (C) to the reaction system, the third stage polymerization is performed. This third stage polymerization is conducted in the same way as the first stage polymerization, in which ηsp/
Through this third stage polymerization, which is carried out under conditions such that the number of components is 2 or less, component (C) is formed as a constitutional unit in a manner that coats the outer surface of the polymer having component (B) as a constitutional unit. A polymer layer can be formed. In this way, an emulsion polymer latex containing a three-stage polymer having a three-layer structure composed of three types of polymers can be obtained.

In addition, during the second and third stage polymerization of the above polymerization reaction stage, it is recommended to carry out the polymerization reaction without adding any additional emulsifier to obtain a three-stage polymer having a homogeneous three-layer structure. This is preferable because it can generate .

The composition according to the present invention comprises a suspension polymerization solution containing the polyvinyl chloride resin as the component (I) and the component (II).
) An emulsion polymer latex containing a three-stage polymer is mixed uniformly in a liquid state, and then a coagulant is added to co-precipitate the blue component, and the blue component is then separated. Can be done.

In this case, the mixing ratio of component (I) and component (II) is 0.00 parts by weight of component (II) as a three-stage polymer contained therein relative to 100 parts by weight of the polyvinyl chloride resin in component (I). The amount is 1 to 25 parts by weight, preferably 0.3 to 15 parts by weight. If the mixing ratio is less than 0.1 part by weight (
There is a tendency for component n) to exhibit insufficient lubricity as a processing aid, and if it exceeds 25 parts by weight, secondary processability and lubricity tend to be impaired.

The coagulant is usually used in the form of a solution, and its type is not particularly limited; for example, sulfuric acid aqueous solution, hydrochloric acid aqueous solution, sodium chloride aqueous solution, etc. can be used.

The coprecipitated (I) and (II) m fractions are separated by a method such as filtration or centrifugation.

The composition according to the present invention thus obtained can then be subjected to various treatments such as washing, dehydration, and drying as necessary.

In addition, the composition according to the present invention may optionally include a stabilizer,
A lubricant, an impact-resistance reinforcing agent, a plasticizer, a coloring agent, a filler, a foaming agent, etc. can also be blended.

[Examples of the Invention] The present invention will be described in further detail below with reference to Examples and Comparative Examples. In addition, in Examples and Comparative Examples, "1 part" represents "part by weight".

Example 1 5 kg of ion-exchanged water, 6 g of 80% partially saponified polyvinyl alcohol, 3 g of methyl cellulose, and 9 g of dilauroyl peroxide were put into a polyvinyl Peng 109 stainless steel autoclave.Then, the system was degassed. After purging the tank with nitrogen gas, 1.5 kg of vinyl chloride monomer was added. Thereafter, a polymerization reaction was carried out at 65° C. with stirring for 6 hours to obtain a suspension of polyvinyl chloride resin with a yield of 90%.

3. In a reaction vessel equipped with a latte stirrer and a reflux condenser, add 280 g of ion-exchanged water, 1.5 g of sodium dioctyl sulfosuccinate, 0.2 g of ammonium persulfate, and 30 g of methyl methacrylate (component -(A)).
9 A mixture of 0.003 g of n-octyl mercaptan was charged.Next, the inside of the reactor was purged with nitrogen gas, and the inside of the reactor was heated to 65°C while stirring.

Thereafter, the mixture was stirred at this temperature for 2 hours. Next, a mixture of component (B), 30 g of methyl methacrylate, 20 g of n-butyl acrylate, and 0.5 g of n-octyl mercaptan, was added dropwise over 1 hour, and after the addition was complete, the mixture was further stirred for 2 hours.

Thereafter, a mixture of 20 g of methyl methacrylate and 0.002 g of n-octyl mercaptan as component (C) was added to the reaction vessel over a period of 30 minutes, and the mixture was further stirred for 2 hours to carry out a polymerization reaction to obtain an emulsion polymer latex. Note that the polymerization rate was 99% and the degree of polymerization was 720.

The thus obtained suspension polymerization solution containing polyvinyl chloride resin and emulsion polymer latex containing three-stage polymer were added to 100 parts of polyvinyl chloride resin in the suspension. The polymers were mixed in amounts of 1.3 and 5 parts (hereinafter, these mixing ratios will be referred to as r 1 phr J
, “abbreviated as 3 phr J and r5 phr J)0 then,
After stirring at 65°C for 30 minutes, 0.2% sulfuric acid aqueous solution was added in an amount equivalent to three times the solid content in the mixed latex, and the mixture was stirred to co-precipitate the polyvinyl chloride resin and the three-stage polymer. Ta. Thereafter, the coagulated material was separated, and then washed, dehydrated, and dried by conventional methods to obtain a polyvinyl chloride resin composition.

The processing characteristics and other physical properties of these polyvinyl chloride resin compositions were evaluated. In addition, during the evaluation, processing characteristics and other physical properties were evaluated for test compound compositions with the following compositions, except that the amount of the three-stage polymer added to 100 parts of polyvinyl chloride resin was varied as described above. .

[Test blended composition] Polyvinyl chloride resin 100 parts three-stage polymer
Variable dibutyltin mercaptide
2-part glycerin monostearate 1
Comparative Example 1 The polyvinyl chloride resin-containing suspension polymerization solution obtained in Example 1 was centrifuged, washed, dehydrated, and dried to obtain polyvinyl chloride resin powder (degree of polymerization: 720).

Further, the emulsion polymer latex containing the three-stage polymer obtained in Example 1 was coagulated with a 0.2% aqueous sulfuric acid solution in an amount equivalent to three times the amount of the latex, and then washed, dehydrated, and dried to form a three-stage polymer. A combined powder was obtained.

A test blended composition was obtained by mixing these polyvinyl chloride resin powders and three-stage polymer powders in the same proportions as in Example 1 above.

Comparative Example 2 Component (B) was 30 g of styrene and 20 g of butyl acrylate.
A test blended composition was obtained in the same manner as in Example 1, except that 0.5 g of n-octyl mercaptan was used.

Comparative Example 3 In the reaction vessel used in Example 1, 280 g of ion-exchanged water, 1.5 g of sodium dioctyl sulfosuccinate, 0.2 g of ammonium persulfate, and 3 methyl methacrylate (component (B)) were added.
A mixture of 0 g of n-butyl acrylate, 20 g of n-butyl acrylate, and 0.5 g of n-octyl mercaptan was charged. Next, after purging the inside of the container with nitrogen gas, the reaction container was heated to 65°C while stirring.
The mixture was stirred for 2 hours while maintaining this temperature.

After that, 50 g of methyl methacrylate of component (C) and n-
A mixture with 0.005 g of octyl mercaptan was added over 30 minutes, and the polymerization was completed by further stirring for 2 hours.
A test blended composition was then obtained in the same manner as in Example 1.

Comparative Example 4 In a reaction vessel, 280 g of ion-exchanged water, 1.5 g of dioctyl sodium sulfosuccinate, 0.2 g of ammonium persulfate,
80 g of methyl methacrylate, 20 g of n-butyl acrylate, and 1.2 g of n-year-old ctyl mercaptan were charged.Next, after purging the inside of the container with nitrogen gas, the temperature of the reaction container was raised to 65°C under stirring and this temperature was maintained. Leave it still 2
Polymerization was completed by stirring for a period of time, and a test blended composition was obtained in the same manner as in Example 1.

Comparative Example 5 Using only the polyvinyl chloride resin powder obtained in Comparative Example 1,
A test formulation composition was prepared in which no three-stage polymer was blended.

The following tests (common to the following Examples and Comparative Examples) were conducted on each of the test formulation compositions of Example 1 and Comparative Examples 1 to 5 obtained as described above. In the following, the term "polymer" refers to a three-stage polymer in Examples, and the corresponding component in Comparative Examples.

The results are shown in Table 1.

Roll slipperiness: Using a 6 inch roll, roll cross wire temperature 2
A sample of 100 g was kneaded at 00° C. x 195° C. with a roll spacing of 1 mm, and the peelability from the roll surface was compared after 5 minutes. Evaluation is based on the usual 5-point system, with 5 being "g! The highest value is 1, and the lowest value indicates peeling, and the closer the value is to 5, the greater the slipperiness. Polymer loadings of 1 phr, 3 phr and 5 phr.

Stickness two-roll kneading temperature 205℃ x 200℃,
A sample of 100 g was kneaded with a roll spacing of 1 mm, and the time required for the sheet to stick to the roll surface and not peel off was measured. The longer this time, the better the durability of slipperiness at high temperatures. Polymer addition: 1 phr.

Gelation characteristics: Indicates the time (Tmax) until the maximum torque is reached when measured using a Nibrabender plastic coder, and the smaller the value, the faster the gelation occurs.Temperature 17
0℃, rotation speed 30 rpm, filling amount 50g, preheating 5 minutes,
Polymer addition: 3 phr.

Playout: When molding was performed using a mold, the state of adhesion to the mold was visually observed. In Table 1, O represents less adhesion, × represents more adhesion, and Δ represents an intermediate value.

The amount of transparent polymer added is 3 to polyvinyl chloride resin.
After kneading for 5 minutes using a test blended composition that is phr, it was pressed under pressure at 185°C to create a press plate with a thickness of 2cm, and then measured with an integrating sphere type haze meter (JIS
(measured according to K-6714).

High-temperature tensile elongation: A test blend composition in which the amount of polymer added was 3 phr based on the polyvinyl chloride resin was kneaded for 5 minutes, then pressed at 185°C, and a press plate with a thickness of [■] was kneaded for 5 minutes. After creation, the elongation at break was measured using a Tensilon tensile tester with a temperature controlled at 150° C. as a dumbbell specimen. The tensile speed was 50 ram/lll1n.

As is clear from the evaluation results shown in Table 1, a suspension polymerization solution containing a polyvinyl chloride resin and an emulsion polymer latex containing a three-stage polymer are mixed in a liquid state and then co-precipitated. The composition of Example 1 was superior to the composition of Comparative Example 1, which was obtained by mixing the same components in powder form, in terms of roll lubricity and especially sustained lubricity as indicated by the stickness value. In addition, the gelation promoting effect and plate-out preventing effect were also very excellent.

In addition, the composition of Comparative Example 2, which has the same composition except that the component corresponding to the component (B) of Example Processing was changed, has excellent initial roll slipperiness compared to the composition of Example 1. However, it was significantly inferior in terms of sustained lubricity and plate-out prevention effect.

Furthermore, as components corresponding to the three-stage polymer that is a constituent component of the composition of Example 1, (B) and (C
The compositions of Comparative Examples 3 and 4 whose constituent components were a two-stage polymer using a component corresponding to component (B) of Example 1 and a first-stage polymer using a component corresponding to component (B) of Example 1 were 1
The composition was inferior in terms of plate-out prevention effect.

Examples 2 to 5 and Comparative Examples 6 to 8 The monomer composition of component (A) was changed to methyl methacrylate 30
3 in the same manner as in Example 1, except that the component (B) was 30 g of n-butyl methacrylate and 20 g of ethyl acrylate, and the component (C) was 20 g of methyl methacrylate.
An emulsion polymer latex containing a stage polymer was obtained. However, using n-octyl mercaptan, the polymer ηsp/c constituting each layer was TA-sectioned as shown in Table 2. The obtained emulsion polymer latex and the suspension polymer obtained in Example 1 were mixed in the same proportion as in Example 1, and then subjected to treatment such as coprecipitation to obtain each polyvinyl chloride resin composition. Ta.

The same evaluations as in Example 1 were performed for each of the test blended compositions obtained. The results are shown in Table 2.

As is clear from Table 2, η of component (A) and component (C)
When sp/c was less than 2, the lubricity was poor, the gelation rate was slow, and the tensile elongation at high temperatures was also poor. Also (B)
When ηsp/c of the component exceeded 1 (Comparative Example 7), the slipperiness was extremely poor. Compared to the compositions of these comparative examples, the compositions of the examples were superior in overall processability.

Examples 6 to 8 and Comparative Examples 9 to 10 (B) component was all ethyl methacrylate) 30g and n-
20 g of butyl acrylate was used, the monomer composition of component (A) and component (C) were changed as shown in Table 3, and the ηsp/c of the polymer constituting each layer was changed as shown in Table 3. An emulsion polymer latex having a three-stage polymer was obtained in the same manner as in Example 1. The obtained emulsion polymer latex and the suspension polymerization liquid obtained in Example 1 were mixed at the same blending ratio as in Example 1, and then subjected to treatment such as coprecipitation to obtain each polyvinyl chloride resin composition. Ta.

The obtained test compositions were evaluated in the same manner as in Example 1. The results are shown in Table 3.

As is clear from the evaluation results shown in Table 3, even if the (B) component and (C) component are exactly the same as in Example 6, (A)
When the content of n-butyl acrylate, a comonomer of methyl methacrylate, which is a constituent unit of the component, exceeds 20% (composition of Comparative Example 9), the stickiness is significantly inferior to that of the composition of Example 6. Ta.

In addition, even if the components (A) and (B) are exactly the same as those in Example 7, if the content of ethyl methacrylate as a comonomer of methyl methacrylate in component (C) exceeds 50% (composition of Comparative Example 10). The stickiness of the composition of Example 7 was significantly inferior to that of the composition of Example 7.

Examples 9 to 11 and Comparative Examples 11 to 12 Emulsion polymer latexes of three-stage polymers were obtained in the same manner as in Example 1, except that component (B) was changed as shown in Table 4. The obtained emulsion polymer latex and the suspension polymerization liquid obtained in Example 1 were mixed at the same blending ratio as in Example 1, and then subjected to treatment such as coprecipitation to obtain each polyvinyl chloride resin composition. .

The same evaluations as in Example 1 were performed for each of the test blended compositions obtained. The results are shown in Table 4.

As is clear from the evaluation results shown in Table 4, (B) r
When the methyl methacrylate content in the composition was less than 30% (composition of Comparative Example 11), the roll slipperiness and stickiness decreased, and the gelation rate became extremely slow. In addition, the content of methyl methacrylate is 70%
(composition of Comparative Example 12), roll slipperiness and stickiness decreased.

As is clear from the evaluation results shown in Tables 1 to 4 above, the compositions of the Examples have superior lubricity, mold release properties, and gelling properties, and are superior to the compositions of the Comparative Examples. It was found that the tensile strength, etc., were excellent.

[Effects of the Invention] As explained above, the production method of the present invention involves mixing a suspended ffi polymerization solution containing a polyvinyl chloride resin as a constituent component and an emulsion polymer latex containing a three-stage polymer into a liquid state. By directly mixing the components and then coprecipitating them, the processability of the resulting composition can be greatly improved.

Further, the composition obtained by the production method of the present invention contains a three-stage polymer having a three-layer structure consisting of a polymer having component (A), components (B) and (C) as constituent units. By including it, it has the following excellent effects.

That is, it has excellent secondary processability, such as increasing the gelation rate of the polyvinyl chloride resin contained in the composition and improving the high temperature tensile elongation of the molded product. In addition, component (B), which is a structural unit of the polymer constituting the intermediate layer of the three-stage polymer, also contains methacrylic acid alkyl ester, which has good compatibility with polyvinyl chloride resin, so it does not cause bleeding or plate formation. The problem of occurrence of outs that occurs during normal molding processing is also eliminated. Furthermore, the transparency of the molded product is not impaired, and although the methacrylic acid alkyl ester contained in component (B) is thought to have strong adhesion to metal surfaces, it actually has a slippery property. It also has the surprising effect of not inhibiting the sustainability of lubricity, but rather enhancing the sustainability of lubricity.

The above effects cannot be achieved with conventionally known compositions.For example, styrene, which has poor compatibility with polyvinyl chloride resin, is added as component (B), which is the structural unit of the polymer that corresponds to the intermediate layer of a three-layer structure. In this case, bleeding, plate-out, etc. are likely to occur, which not only increases the amount of deposits on the mold etc. during the molding process, but also reduces the transparency of the molded product. A similar phenomenon also puts a limit on the long-term sustainability of lubricity. Furthermore, even if component (A), component (B) and component (C) are used alone, or the constituent units of component (A), component (B) and component (C), can be used simultaneously in one step. Excellent lubricity cannot be obtained even by copolymerization, and the two-layer structure has a polymer layer consisting of component (B) as a core and a polymer layer consisting of component (A) or (C) on the outside. In the case of [for example, obtained by two-stage polymerization in which component (B) is first polymerized and then the monomer that is the constituent unit of component (A) is polymerized in the presence of the polymer], unlike the case of a three-layer structure, Using component (A) as the core without using component (C), which has poor long-term sustainability of # shapeability and slipperiness from the metal surface, and greatly reduces gelling properties and secondary processability, Even when the outer layer contains a polymer containing component (B) as a constituent unit, the long-term sustainability of mold releasability and lubricity from metal surfaces is still key, and the gelling properties and secondary processability are also greatly improved. It declines.

Claims (1)

[Scope of Claims] (I) A suspension polymerization solution containing a polyvinyl chloride resin in which at least 80% by weight of its structural units are vinyl chloride units, and 100% by weight of the polyvinyl chloride resin contained in the polymerization solution. (II) (A) A polymer or copolymer in which at least 80% by weight of the constituent units are methyl methacrylate units, wherein 0.1 g of the polymer or copolymer is dissolved in 100 ml of chloroform. In the presence of (B) an alkyl having 1 to 18 carbon atoms, 10 to 45 parts by weight of a solution obtained by dissolving the solution at 25° C. has a reduced viscosity (ηsp/c, the same applies hereinafter) of 2 or more; 40 to 70 parts by weight of a mixture of 30 to 70% by weight of methacrylic acid alkyl ester and 70 to 30% by weight of acrylic acid alkyl ester having groups such that ηsp/c of component (B) alone is 1 or less. In the presence of a two-stage polymer consisting of a polymer having component (A) and component (B) as constituent units obtained by polymerization under the following conditions, 50 to 100% by weight of (C) methyl methacrylate and the methyl methacrylate 5 to 40 parts by weight of methyl methacrylate or a mixture containing it, consisting of 50 to 0% by weight of a monomer copolymerizable with ]; An emulsion polymer latex containing a three-stage polymer obtained by polymerizing the (C) component alone under conditions such that η sp / c becomes 2 or more; 0.1 to 25 parts by weight when combined; is characterized in that after mixing, a coagulant is added to the mixture to coprecipitate the components (I) and (II), and then they are separated. A method for producing a polyvinyl chloride resin composition.