JPS6354017B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to vinyl chloride resin compositions having good processing and physical properties. Polyvinyl chloride is widely used due to its excellent physical and chemical properties, but the processing temperature is close to the thermal decomposition temperature, making the molding area narrow and the gelation rate slow. I have the above problem. Although it is well known that the addition of plasticizers solves some of these drawbacks, it also leads to a decrease in the mechanical properties of other molded parts with problems such as plasticizer volatilization, and cured polyvinyl chloride. It is far from a complete solution to the applications of It improves productivity by slowing down the gelation rate of the resin during the molding process of vinyl chloride resin and reducing the adhesion to the metal surface of the molding machine.
In addition, vinyl chloride resin is used to smooth the surface of molded products, give them a gloss that does not change even after long-term continuous molding, and enable deep drawing of molded products. A number of copolymers that are compatible with these materials have been investigated as processing aids, with great success in some applications.
The main ones currently used on the market are copolymers whose main component is methyl methacrylate. These have a great effect of accelerating the gelation rate and greatly improve the secondary processability, especially by increasing the tensile elongation at high temperatures. (also called "Fish eye"). In particular, when it is blended with soft vinyl chloride resin, it exhibits almost no compatibility and is scattered as countless ungelled substances, which significantly reduces the commercial value.In this sense, it cannot be applied to the soft field. It is extremely difficult. A composition that solves the above problems all at once, that is, maintains the transparency of vinyl chloride resin,
A processing aid that improves elongation at high temperatures and secondary processability such as deep drawing, and also provides excellent dispersibility and processing properties not only for hard vinyl chloride resins but also for soft vinyl chloride resins. has been devised, but from the viewpoint of improving productivity and saving energy, when processing vinyl chloride resin, it is necessary to have good dispersibility for vinyl chloride, quick gelation, and in the blending process before processing. There has been a growing demand for no torque to be applied during kneading in Henschel mixers and the like. Furthermore, due to the difference in compatibility of vinyl chloride and processing aids with plasticizers, there is a phenomenon of fusion of processing aids during blending, and the resulting generation of ungelled materials during film sheet processing, especially when using soft vinyl chloride resin. There is a need to greatly improve dispersibility, and the above compositions have their limitations, and depending on the formulation, processing aids may adhere to the vessel walls during blending, so we cannot fully meet market demands. The situation cannot be said to be satisfactory. The inventors of the present invention have conducted a wide range of studies while taking the above points into consideration, and have found that while having the excellent processing properties shown by the polymethyl methacrylate system, it also has excellent soft dispersibility, and has a high gelation rate. However, with the aim of quickly obtaining a composition that does not adhere to or fuse to the vessel wall during blending, the present invention was arrived at after repeated studies. The present invention provides () a vinyl chloride polymer or copolymer in which at least 80% by weight is a vinyl chloride component;
99.9 to 70 parts by weight and () (A) at least 60% by weight
is methyl methacrylate, and the reduced viscosity (ηsp/C) measured at 25°C of a solution of 0.1 g of the polymer in 100 ml of chloroform is 2 or more, exceeding 45 parts by weight. (B) Mixture 5 consisting of 30 to 70% by weight of styrene and 70 to 30% by weight of acrylic ester in the presence of 70 parts by weight.
Parts by weight to less than 50 parts by weight are polymerized under conditions such that ηsp/C of component (B) is 1 or more, and in the presence of the obtained polymer containing both components (A) and (B), ( C) Add 5 to 25 parts by weight of a monomer or monomer mixture containing at least 80% by weight of methyl methacrylate so that the ηsp/C of component (C) is 2.
A three-stage polymer obtained by polymerizing under the above conditions (the sum of components (A), (B), and (C) is 100 parts by weight) 0.1 to 30
This is a novel vinyl chloride-based resin composition having good processability and physical properties. In the present invention, at least 80% by weight of the vinyl chloride polymer as component () is a vinyl chloride component, and the amount of component () added is 0.1 to 30 parts by weight relative to 99.9 to 70 parts by weight. If it is less than 0.1 part, no effect will be exhibited, and if it exceeds 30 parts, the original characteristics of vinyl chloride resin will be impaired. The characteristics of component () in the present invention are a copolymer of styrene and acrylic acid ester with poor compatibility and good fluidity, and (B) a methyl methacrylate polymer on the inside and outside of the component (A). (C) Components are arranged in a so-called Sandermanch structure. This Sanderch structure has at least 60% by weight methyl methacrylate and ηsp/C of 2.
In the presence of latex containing component (A), which is the above polymer or copolymer, raw materials for component (B), which is a mixture of 30 to 70% by weight of styrene and 70 to 30% by weight of acrylic ester, are 55 parts by weight of component (B) ηsp/C
Polymerizes under conditions such that 1 or more, and further (A) and
In the presence of a latex containing component (B), 5 to 25 parts by weight of the raw material for component (C), which is a monomer or monomer mixture containing at least 80% by weight of methyl methacrylate, is added to the It is obtained by applying a three-stage polymerization method in which polymerization is performed under conditions such that C becomes 2 or more. The ηsp/C of each polymer of components (A) to (C) is the value when each component is polymerized alone, and can be arbitrarily adjusted by changing the chain transfer agent, polymerization conditions, etc. Each polymer (A) to (C)
The method for determining the component ηsp/C is as follows. In advance, each component is polymerized alone using a specified emulsifier, catalyst, and polymerization temperature, and a calibration curve of ηsp/C is obtained using the amount of chain transfer agent as a variable. When polymerizing the three-stage polymer, the polymerization conditions were the same as those for obtaining the calibration curve, and the ηsp/C with respect to the amount of chain transfer agent added was read from the calibration curve, and the value was taken as the ηsp/C of each component. In order to form this sandwich structure, it is necessary to carry out the polymerization in the presence of the second and subsequent stages without adding an emulsifier as much as possible, so that component (B), component (C)
Formation of polymers of individual components must be suppressed.
This composition has a relatively soft high molecular weight methyl methacrylate component with low fluidity as a core, and a composition obtained by polymerizing component (B) with good fluidity around the core, which is blended with vinyl chloride resin. As components (B) and (C), they not only accelerate the gelation rate of vinyl chloride resin and have excellent effects on the high-temperature tensile elongation and secondary processability of molded products, but also have good fluidity. Due to the mutual effect of the vinyl chloride and methyl methacrylate components that are included, it does not form blocks during blending, does not adhere to the vessel wall, and improves dispersibility in soft blends. It has the surprising effect of being able to solve difficult problems such as the generation of ungelled substances, and also not impairing transparency. Note that if component (B) is polymerized under conditions such that ηsp/C1 is less than this, these effects will be impaired. The composition of the present invention has the advantage of increasing the torque (kneading resistance) during molding, forming blocks during blending, and preventing molding, which is seen in conventional vinyl chloride resin compositions containing a polymer containing methyl methacrylate as a main component. This is a composition that has improved the drawbacks such as residual ungelled substances in the product. The amount of component (A) in 100 parts by weight of component () in the composition of the present invention is suitably more than 45 parts by weight to 70 parts by weight, preferably more than 45 parts by weight to 60 parts by weight. If it exceeds 70 parts by weight, blocks will be formed during blending and torque will increase, and if it is less than 45 parts by weight, soft dispersibility will be impaired. ηsp/C needs to be 2 or more; if it is less than 2, no effect on the processability of polymethyl methacrylate is observed, and (B)
The mutual effect with the other components also decreases, and the dispersibility in soft polyvinyl chloride also decreases. Component (A) is polymethyl methacrylate or a copolymer in which at least 60% by weight is methyl methacrylate, but there are no particular restrictions on the partner monomer of the methyl methacrylate polymer, and it may vary depending on the intended use of the final composition. Appropriate monomers can be used,
For example, one or more of aromatic vinyl, unsaturated nitriles, vinyl esters, methacrylic esters, acrylic esters, etc. are used in an amount of 40% or less. If the amount used exceeds 40%, the compatibility of the composition with the vinyl chloride resin decreases, which is not preferable. Furthermore, it is also possible to use polyfunctional monomers such as divinylbenzene and allyl methacrylate in component (A), but in this case, the amount used is preferably 1% or less. The amount of component (B) in 100 parts by weight of component () is 5 parts by weight to less than 50 parts by weight, preferably 20 to 30 parts by weight. If the amount is less than 5 parts by weight, soft dispersibility will be impaired, and if it is more than 50 parts by weight, gelation will be extremely slow. The major feature of component (B) is that it copolymerizes styrene and acrylic ester, and by using styrene as an essential component and polymerizing under conditions such that ηsp/C is 1 or more. Excellent effects are seen in improving soft dispersibility and blocking resistance. The styrene that constitutes component (B) is 30 to 70% by weight,
The acrylic ester content is 70 to 30% by weight, and if the acrylic ester content is 70% or more, the gelation of the final product will be extremely slow, resulting in poor surface properties. Examples of acrylic esters include ethyl acrylate, n-butyl acrylate,
Isobutyl acrylate, 2-ethylhexyl acrylate, etc. can be used, but n-butyl acrylate is particularly preferred, and copolymerization with other acrylic esters is also possible. Styrene and acrylic ester in component (B) must be copolymerized randomly, and styrene and acrylic ester must not be graft-polymerized sequentially. This is because, if a block of bonds such as butyl acrylate is present in the product, the composition obtained by mixing the final product with the vinyl chloride resin will completely lose its transparency. The amount of component (C) in 100 parts by weight of component () is 5 to 25 parts by weight, preferably around 15 parts by weight. If the amount is less than 5 parts by weight, excellent block resistance, soft dispersibility and secondary processability cannot be fully exhibited. Moreover, if it exceeds 25 parts by weight, poor soft dispersion occurs, and ungelled substances are often generated. From the viewpoint of secondary processability, component (C) must be polymerized under conditions such that ηsp/C is at least 2 or more. When synthesizing three-stage polymers, emulsion polymerization is used.
As the emulsifier used therein, commonly known emulsifiers can be used, and as the polymerization initiator, water-soluble, oil-soluble and redox-based ones can be used. The ηsp/C of the polymer can be arbitrarily adjusted by using a chain transfer agent, polymerization temperature, etc. in a conventional manner. The method of mixing the three-stage polymer () with the vinyl chloride resin () is not limited and may be any commonly used method. The obtained vinyl chloride resin composition can also contain stabilizers, lubricants, impact-strengthening agents, plasticizers, colorants, fillers, etc., if necessary. In the following examples, parts represent parts by weight. Examples 1-3 Distilled water in a reaction vessel with stirrer and reflux condenser
280 parts, dioctyl sulfosuccinate sodium 1.5
1 part, ammonium persulfate (0.2 parts) and a mixture of component (A) in Table 1. After purging the inside of the container with nitrogen, the temperature of the reaction container was raised to 65° C. with stirring, and the mixture was heated and stirred for 2 hours. Subsequently, the mixture of component (B) was added over 1 hour, and after the addition was completed, stirring was continued for 2 hours. Thereafter, the mixture of component (C) was added for one hour or so, and stirring was continued for an additional two hours to complete the polymerization.

[Table] After cooling, the obtained emulsion was salted out using aluminum chloride, filtered, washed, and dried to obtain each sample. Three parts of each of the above samples were mixed in a Henschel mixer with 100 parts of polyvinyl chloride (average degree of polymerization 715), 2.0 parts of dibutyltin malate, 1.5 parts of an epoxy stabilizing agent, and 0.5 parts of a lubricant, and the internal temperature was 120°C. Blending was completed at , and subjected to gelation properties, gloss, and high temperature tensile tests. Furthermore, 40 parts of dioctyl phthalate (DOP) was added to this mixture, and the mixture was tested for soft dispersibility and adhesion to the vessel wall. The processability measurement results of the above vinyl chloride resin composition are summarized in Table 2.

【table】

[Table] Examples 4-5 Distilled water in a reaction vessel equipped with a stirrer and reflux condenser
280 parts, dioctyl sulfosuccinate sodium 1.5
1 part, ammonium persulfate 0.2 part and a mixture of component (A) in Table 3 were charged, and after purging the inside of the container with nitrogen, the temperature of the reaction container was raised to 65° C. with stirring, and the mixture was heated and stirred for 2 hours. Subsequently, the mixture of component (B) was added over 1 hour, and after the addition was completed, stirring was continued for 2 hours. Thereafter, a mixture of component (C) was added for one hour or so, and stirring was continued for another two hours to complete the polymerization.

[Table] After cooling, the emulsion obtained with the above composition was salted out using aluminum chloride, filtered, washed and dried to obtain each sample. Three parts of each of the above samples were mixed in a Henschel mixer with 100 parts of polyvinyl chloride (average degree of polymerization 715), 2.0 parts of dibutyltin malate, 1.5 parts of an epoxy stabilizing agent, and 0.5 parts of a lubricant, and the internal temperature was 120°C. Blending was completed at , and subjected to gelation properties, gloss, and high temperature tensile tests. Additionally, 40 parts of DOP was added to this mixture and subjected to tests for soft dispersibility and adhesion to vessel walls. The processability measurement results of the above vinyl chloride resin composition are summarized in Table 4.

[Table] From Tables 2 and 4, when the composition ratio of component (A), component (B), and component (C), ηsp/C, etc. are outside the scope of the present invention, it has excellent processability. It is clear that no composition is obtained.

Claims (1)

[Scope of Claims] 1 () A vinyl chloride polymer or copolymer 99.9 in which at least 80% by weight is a vinyl chloride component
~70 parts by weight and ()(A) at least 60% by weight methyl methacrylate, 0.1 g in 100 ml chloroform
(B) Styrene 30 in the presence of more than 45 parts by weight to 70 parts by weight of a polymer or copolymer having a reduced viscosity (ηsp/C) of 2 or more measured at 25°C for a solution containing a polymer of (B) 5 parts by weight of a mixture consisting of ~70% by weight and 70-30% by weight of an acrylic ester ~
(C) Methyl in the presence of a polymer containing both components (A) and (B) obtained by polymerizing less than 50 parts by weight of component (B) under conditions such that ηsp/C is 1 or more. Polymerization ((A), (B), ( A vinyl chloride resin composition having good processability and physical properties, comprising 0.1 to 30 parts by weight of a three-stage polymer obtained by C) (total of component C) is 100 parts by weight.