JP2008208250A - Vinyl chloride-based resin molded form - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vinyl chloride-based resin molded form having a combination of flame retardancy meeting the requirements of FM4910 Flammability Test (FMRC: Clean Room Materials Flammability Test) and high impact resistance ranging from room temperature to lower temperatures. <P>SOLUTION: The vinyl chloride-based resin molded form is such that the proportion of chlorine in the organic components therein stands at 50-64 mass%. This molded form is obtained by incorporating 100 pts.mass of a vinyl chloride-based resin with 8-15 pts.mass of an impact resistance improver as a copolymer of a polymethyl methacrylate component and a rubber component with a glass transition point of -55°C or lower. In this molded form, the compatibility of the impact resistance improver is increased owing to the polymethyl methacrylate component, while the impact resistance of the molded form is increased to the range to lower temperatures owing to the above rubber component, and the flame retardancy of the molded form is increased by suppressing the amount of the impact resistance improver therein to 15 pts.mass or lower and owing to a large amount of the chlorine therein. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vinyl chloride resin molded body, and particularly to a vinyl chloride resin molded body having both flame retardancy and impact resistance.

  Since vinyl chloride resin has good moldability, is inexpensive, and has good chemical resistance, it is widely used in various fields including industrial materials.

  Such a molded body of vinyl chloride resin has good flame retardancy because it contains a large amount of chlorine, but when it is exposed to a high temperature of 200 ° C. or more due to a fire or the like, it causes thermal decomposition and generates a large amount of smoke. At the same time, corrosive gases such as chlorine gas and hydrogen chloride gas are generated. Therefore, in order to prevent this, a flame retardant is conventionally improved by adding a phosphorus flame retardant, a halogen flame retardant, or a water-containing compound such as magnesium hydroxide to the vinyl chloride resin. In addition, the present applicant has already proposed a vinyl chloride resin molded article in which a considerably large amount of titanium oxide is contained in a vinyl chloride resin to enhance flame retardancy (Patent Document 1).

On the other hand, 40 to 70% by mass of a vinyl chloride resin having a chlorine content of 60 to 70% by mass, 10 to 40 parts by mass of at least one impact modifier selected from the group of acrylic rubber, chlorinated polyethylene, and AES resin, and styrene And a composition comprising 15 to 40% by mass of a copolymer of a vinyl compound and a vinyl cyanide compound and 0.01 to 5% by mass of a hindered amine light stabilizer, and good weather resistance, impact resistance, heat resistance, A vinyl chloride resin composition imparted with flame retardancy is also known (Patent Document 2).
JP 2000-313748 A JP-A-6-145450

  However, when a flame retardant or a water-containing compound is contained in a vinyl chloride resin as in the prior art, or titanium oxide is contained in a vinyl chloride resin as in Patent Document 1, the flame resistance is improved, but the mechanical strength is increased. In particular, there is a problem that the impact strength is reduced.

  On the other hand, the vinyl chloride resin composition of Patent Document 2 uses a vinyl chloride resin having a high chlorination degree in order to impart flame retardancy. Although it is inferior in impact, impact modifiers such as acrylic rubber, chlorinated polyethylene, and AES resin are added to cover this, so resistance to resistance at 23 ° C. measured in accordance with ASTM D-256. Impact strength is not bad. However, the quality of impact strength in a low temperature range of 0 ° C. or lower is unclear, and it is not disclosed how much the impact modifier is synthesized to have a glass transition point. The quality of the impact strength cannot be estimated. If the glass transition point of the impact modifier is not so low (for example, about −20 to −30 ° C.), the impact resistance strength in the low temperature range (for example, around −20 ° C.) is greatly reduced and good. Impact resistance cannot be expected.

  The present invention has been made under the above circumstances, and the problems to be solved are flame retardancy that can pass the flame retardancy test (FMRC) of FM4910, and good impact resistance from room temperature to low temperature range. Another object of the present invention is to provide a vinyl chloride resin molded body having both properties.

  In order to solve the above problems, a vinyl chloride resin molded body according to the present invention is a vinyl chloride resin molded body having a chlorine ratio of 50 to 64% by mass in the organic component in the molded body, and has a glass transition point. Is characterized by containing 8 to 15 parts by mass of an impact modifier obtained by copolymerizing a rubber component having a temperature of −55 ° C. or less and a polymethyl methacrylate component with respect to 100 parts by mass of the vinyl chloride resin. is there.

  In the vinyl chloride resin molded article of the present invention, the ratio of the rubber component in the impact resistance improver is preferably more than 50% by mass and 95% by mass or less, and the number average particle diameter of the impact resistance improver is 0. It is preferably 10 to 0.50 μm. The rubber component is preferably any one of styrene butadiene rubber, silicon rubber, and butyl acrylate rubber having a glass transition point of −55 ° C. or lower.

The vinyl chloride resin molded article of the present invention has both good flame retardancy and good impact resistance from room temperature to low temperature range, and flame retardancy index measured based on the flame retardancy test (FMRC) of FM4910 FPI is 6 or less, smoke index SDI is 0.4 or less, Charpy impact strength at 23 ° C. measured based on JIS K 7111-1 is 7 kJ / m ² or more, measured according to JIS K 7111-1. The Charpy impact strength at 0 ° C. is 5 kJ / m ² or more, and the Charpy impact strength at −20 ° C. measured according to JIS K 7111-1 is 4 kJ / m ² or more.

  The above flame retardant test (FMRC) of FM4910 is a flame retardant test of clean room materials listed as Class Number 4910 of the evaluation standard established by the industry mutual insurance organization (factory mutual system) based in North America ( FMRC Clean Room Materials Flammability Test).

  In the vinyl chloride resin molded article of the present invention, one copolymer component of the contained impact resistance improver is a polymethyl methacrylate component, and the compatibility between the impact resistance improver and the vinyl chloride resin is good. The impact modifier is contained evenly dispersed, and the impact resistance is enhanced by the rubber component which is the other copolymer component of the impact modifier. In particular, the rubber component has a low glass transition point of −55 ° C. or lower, and rubber elasticity is not significantly impaired even in a low temperature range of 0 ° C. or lower (eg, −20 ° C.). Even in the following low temperature range, it exhibits good Charpy impact strength as described above. Such an effect is remarkably exhibited when the impact resistance improver is contained in an amount of 8 parts by mass or more with respect to 100 parts by mass of the vinyl chloride resin. Since there is a tendency that the heat resistance of the molded body is lowered by a large amount of the impact resistance improving agent, it is necessary to make it 15 parts by mass or less. The fact that the impact resistance improver content is in the range of 8 to 15 parts by mass can demonstrate sufficient Charpy impact strength from room temperature to a low temperature range, which is supported by the data of Examples described later. In addition, since this vinyl chloride resin molded body has a high ratio of chlorine to the organic components (total organic components) in the molded body (hereinafter referred to as the chlorine content of the molded body organic component) as high as 50 to 64% by mass, Good flame retardancy is exhibited by a large amount of chlorine, and the content of the impact modifier that tends to lower the flame retardancy is suppressed to 15 parts by mass or less. It has flame resistance that can pass the flammability test (FMRC).

  In particular, when the ratio of the rubber component in the impact resistance improver exceeds 50 mass% and is 95 mass% or less, good impact resistance is exhibited. When the rubber component is less than 50% by mass, it is difficult to sufficiently improve the impact resistance. When the rubber component exceeds 95% by mass, the compatibility of the impact modifier is greatly increased due to the lack of the polymethyl methacrylate component. Therefore, it is difficult to improve the impact resistance.

  Moreover, when the number average particle diameter of the impact resistance improver is 0.10 to 0.50 μm, the dispersibility of the impact resistance improver is good, and the impact from the outside can be sufficiently absorbed by its rubber elasticity. When the number average particle size is larger than 0.50 μm, the dispersibility of the impact modifier is lowered. When the number average particle size is smaller than 0.10 μm, it is difficult to absorb external impacts, and therefore, good impact resistance can be exhibited. It becomes difficult.

  Hereinafter, embodiments of the present invention will be described in detail.

  The vinyl chloride resin molded body of the present invention is molded into a desired three-dimensional shape such as a plate shape, rod shape, tubular shape, irregular shape, etc., and has a vinyl chloride resin as a main component, and an impact resistance improver and In this case, various additives are contained in appropriate amounts as required.

  The vinyl chloride resin that is the main component of this molded body is: 1) Degree of chlorination (“chlorination degree” indicates the proportion of chlorine contained in the vinyl chloride resin or post-chlorinated vinyl chloride resin alone, and The same) is a post-chlorinated vinyl chloride resin of 58% by mass or more and 68% or less, and 2) a resin obtained by mixing a normal vinyl chloride resin having a chlorination degree of about 56% by mass with a chlorinated vinyl chloride resin thereafter. 3) These post-chlorinated vinyl resins or mixed resins are made of a resin obtained by mixing a vinyl acetate resin, an acrylic resin, or the like, and this vinyl chloride resin molded article occupies all organic components in the molded article. The ratio of chlorine (the chlorine content of the molded body organic component) is 50 to 64% by mass. The degree of polymerization of the vinyl chloride resin is not particularly limited, but for the post-chlorinated vinyl chloride resin, those having a polymerization degree of 500 to 1000, preferably 600 to 800, are used. Thereafter, the chlorinated vinyl chloride is used. As for the vinyl chloride resin having a normal chlorination degree to be mixed with the resin, those having a polymerization degree of 500 to 1400, preferably 700 to 1000 are used.

  As described above, the chlorine content of the organic component of the molded body is 50 to 64% by mass, and the post-chlorinated vinyl chloride resin and the vinyl chloride resin mixed with the main component have the above degree of polymerization. In combination with the fact that the flame retardancy is improved by a large amount of chlorine, and the content of the impact modifier is suppressed to 15% by mass or less as will be described later, the flame retardancy test of FM4910 (FMRC It is possible to impart flame retardancy that passes More preferably, the chlorine content of the molded body organic component is 52 to 60% by mass, and more preferably 52 to 56% by mass.

  The impact resistance improver contained in the vinyl chloride resin molded article of the present invention is a copolymer of a rubber component having a glass transition point of −55 ° C. or less and a polymethyl methacrylate component, and depending on the polymethyl methacrylate component. While improving compatibility with a vinyl chloride resin, the impact from the outside is absorbed and reduced by the rubber component, and the impact resistance of the molded body is improved. Such an impact resistance improving agent needs to be contained in an amount of 8 to 15 parts by mass, preferably 8 to 12 parts by mass with respect to 100 parts by mass of the vinyl chloride resin, from the viewpoint of achieving both flame retardancy and impact resistance. More preferably, 8-10 mass parts is contained.

  The rubber component of the impact resistance improver has a glass transition point of −55 ° C. or lower in order to exhibit good impact strength even in a low temperature range of 0 ° C. or lower, for example, in a low temperature range near −20 ° C. The impact resistance improver that uses a rubber component having a glass transition point higher than −55 ° C. as a copolymer component significantly deteriorates the rubber elasticity of the rubber component in a low temperature range, and thus exhibits sufficient impact strength. I can't let you. That is, it is considered that the impact strength at low temperatures increases as the glass transition point of the rubber component decreases. A more preferable glass transition point of the rubber component is −58 ° C. or lower.

  As the rubber component of the impact resistance improver, various rubber components having a glass transition point of −55 ° C. or less can be adopted, but among them, the copolymerization reaction with the polymethyl methacrylate component is easy, and the rubber elasticity is excellent and difficult. Styrene butadiene rubber, silicon rubber, butyl acrylate rubber or the like having a glass transition point of −55 ° C. or less that does not have a concern of adversely affecting the flammability is preferably employed. These rubber components may be adjusted so as to have a more preferable glass transition point of −55 ° C. or lower by adjusting the component composition, reaction density (crosslinking density) and the like during synthesis.

  The ratio of the rubber component in the impact resistance improver is preferably more than 50% by mass and 95% by mass or less. When the rubber component is as small as 50% by mass or less, it is difficult to sufficiently increase the impact resistance. When the rubber component exceeds 95% by mass, the compatibility of the impact modifier due to the lack of the polymethyl methacrylate component. , It becomes difficult to improve the impact resistance. A more preferable ratio of the rubber component is 60 to 92% by mass.

  The number average particle size of the impact modifier is preferably 0.10 to 0.50 μm. When the number average particle size is larger than 0.50 μm, the dispersibility of the impact resistance modifier is lowered, and when it is smaller than 0.10 μm, it is difficult to absorb external impacts. It becomes difficult to demonstrate. A more preferred number average particle size of the impact resistance improver is 0.15 to 0.40 μm.

Since the molded article of the present invention contains the above-mentioned impact resistance improver equally in an amount of 8 to 15 parts by mass with respect to 100 parts by mass of the vinyl chloride resin, from the room temperature range, as supported by the data of the examples described later. Excellent impact resistance up to low temperature range, Charpy impact strength at 23 ° C. measured according to JIS K 7111-1 is 7 kJ / m ² or more, at 0 ° C. measured according to JIS K 7111-1 Charpy impact strength 5 kJ / ^{m 2} or more, Charpy impact strength at -20 ° C. as measured in accordance with JIS K 7111-1 is 4 kJ / ^{m 2} or more. When the content of the impact resistance improver is less than 8 parts by mass, it becomes difficult to give satisfactory impact strength, and when the content exceeds 15 parts by mass, the flame retardancy of the molded product Is not preferable in any case.

  Moreover, as an additive contained suitably in the molded object of this invention, stabilizers, such as an organic tin type, an organic lead type, and a calcium zinc type, a processing aid, such as an acrylic type, a polyethylene type, an ester type, an acrylic type, etc. Examples include lubricants, fillers such as calcium carbonate and titanium oxide, and flame retardants such as metal hydrates (aluminum hydroxide and magnesium hydroxide) and antimony trioxide. The added amount is 1 to 10 parts by mass (preferably 2 to 8 parts by mass) of the stabilizer and 0 to 10 parts by mass (preferably 0.2 to 3 parts) of the processing aid with respect to 100 parts by mass of the vinyl chloride resin. Mass part), the lubricant is 0.1 to 5 parts by mass (preferably 0.1 to 3 parts by mass), the filler is 0 to 30 parts by mass (preferably 1 to 20 parts by mass), and the flame retardant is 0 to 10 parts by mass. Part (preferably 2 to 7 parts by mass). Of the above additives, processing aids, fillers, and flame retardants may not be added.

  The vinyl chloride resin molded article of the present invention is kneaded uniformly by adding 8 to 15 parts by mass of the impact resistance improver to 100 parts by mass of the vinyl chloride resin and adding each of the additives as described above. These are manufactured by molding them into a desired three-dimensional shape such as a plate shape, a rod shape, a tubular shape or an irregular shape by a known extrusion molding method or injection molding method. Moreover, it manufactures also by the well-known calendar press method and the continuous press method.

  Next, more specific examples and comparative examples of the present invention will be described.

[Example 1]
10 parts by mass of the following MBS impact modifier A and 2 parts of butyltin malate stabilizer are added to 100 parts by mass of post-chlorinated vinyl chloride resin having a chlorination degree of 64.5% by mass and a polymerization degree of 670. 0.5 parts by mass, 2.0 parts by mass of acrylic processing aid, 0.5 parts by mass of ester lubricant, 2.0 parts by mass of acrylic lubricant, and 0.6 parts by mass of titanium oxide as a filler A test piece of a vinyl chloride resin molded body was prepared. The chlorine content of the molded body organic component of this test piece is 55.0% by mass.
MBS impact resistance improver A: a copolymer of styrene butadiene rubber (SBR) and polymethyl methacrylate, having a number average particle size of 0.19 μm, a rubber component ratio of 70% by mass, and a glass transition point of the rubber component Is -58 ° C.

The test piece was subjected to a flame retardancy test (FMRC) of FM4910 to obtain a flame retardance index FPI and a smoke index SDI. The results are shown in Table 1 below.
For this test piece, the Charpy impact strength at 23 ° C. was measured based on JIS K 7111-1, and the Charpy impact strength at 0 ° C. and −20 ° C. was measured according to JIS K 7111-1. . The results are shown in Table 1 below.
The Charpy impact strength test piece was a type A notched test piece, which was measured by edgewise impact and parallel impact.

[Example 2]
A test piece of a vinyl chloride resin molded article was prepared in the same manner as in Example 1 except that the MBS impact resistance improver A of Example 1 was changed to the following silicon impact resistance improver B. The flame retardant index FPI, the smoke index SDI, and the Charpy impact strength at 23 ° C., 0 ° C., and −20 ° C. were measured in the same manner as in Example 1. The results are also shown in Table 1 below. In addition, the chlorine-chlorine content rate of the molded body organic component of this test piece is 55.0 mass%.
Silicon-based impact modifier B: A copolymer of silicon rubber and polymethyl methacrylate, having a number average particle size of 0.30 μm, a rubber component ratio of 90% by mass, and a glass transition point of the rubber component of −125 ° C. It is.

[Comparative Examples 1-3]
The MBS impact modifier A of Example 1 was changed to the following MBS impact modifier C in Comparative Example 1, and changed to the following silicon impact modifier D in Comparative Example 2, and Comparative Example 3 Then, a test piece of a vinyl chloride resin molded article for comparison was prepared in the same manner as in Example 1 except that the acrylic impact resistance improver E described below was changed. The Charpy impact strength at 23 ° C., 0 ° C., and −20 ° C. was measured in the same manner as above. And about the test piece of the comparative example 2, the flame-retardant index FPI and the smoke generation index SDI were calculated | required similarly to Example 1. FIG. The results are also shown in Table 1 below.
MBS impact resistance improver C: a copolymer of styrene butadiene rubber and polymethyl methacrylate having a number average particle size of 0.13 μm, a rubber component ratio of 50 mass%, and a rubber component having a glass transition point of −58. ° C.
Silicone impact resistance improver D: A copolymer of silicon rubber and polymethyl methacrylate having a number average particle size of 0.30 μm, a rubber component ratio of 33% by mass, and a glass transition point of the rubber component of −125 ° C. It is.
Acrylic impact modifier E: A copolymer of butyl acrylate rubber and polymethyl methacrylate, having a number average particle size of 0.17 μm, a rubber component ratio of 90 mass%, and a glass transition point of the rubber component of −54. ° C.

As shown in Table 1, as an impact resistance improver, the number average particle diameter is 0.19 μm, the rubber component is a styrene butadiene rubber having a glass transition point of −58 ° C., and the proportion of the rubber component is 70% by mass. The test piece of the vinyl chloride resin molded article of Example 1 in which the improving agent A was contained in 10 parts by mass in 100 parts by mass of a post-chlorinated vinyl chloride resin having a chlorination degree of 64.5% by mass had an FPI of 4. It can be seen that 08 meets FM4910 flame retardant test (FMRC) acceptance criteria of 6 or less, and SDI is 0.14 also meets acceptance criteria of 0.4 or less. The Charpy impact strength is also, 12.19kJ ^/ m 2 at 46.38kJ ^{/ m} 2, 0 ℃ at 23 ° C., a 7.06kJ / ^{m 2} at -20 ° C., the target value (23 ° C. of the present invention 7kJ / ^{m 2} or more, 0 ° C. at 5 kJ / ^{m 2} or more, it can be seen that meets the 4 kJ / ^{m 2} or more) at -20 ° C..

Further, as an impact resistance improver, silicon rubber having a number average particle diameter of 0.30 μm, a rubber component having a glass transition point of −125 ° C., and a silicon-based impact resistance improver B having a rubber component ratio of 90% by mass is chlorine. The test piece of the vinyl chloride resin molded article of Example 2 containing 10 parts by mass in 100 parts by mass of post-chlorinated vinyl chloride resin having a degree of conversion of 64.5% by mass was also FPI 4.83 and SDI 0.8. 11, both satisfies the acceptance criteria of the flame retardancy test (FMRC) of FM4910, also Charpy impact strength also, 11.02kJ ^{/ m} 2 at 36.33kJ ^{/ m} 2, 0 ℃ at 23 ° C., - It can be seen that the target value of the present invention is satisfied, which is 10.03 kJ / m ² at 20 ° C.

On the other hand, as an impact resistance improver, the test piece of Comparative Example 1 containing MBS impact resistance improver C with a rubber component (styrene butadiene rubber) occupying a small proportion of 50% by mass has a Charpy impact strength. , 3.33kJ ^/ m 2 at 3.74kJ ^{/ m} 2, 0 ℃ at 23 ° C., a 2.95kJ / ^{m 2} at -20 ° C., either it can be seen that does not satisfy the target value of the present invention. Further, the test piece of Comparative Example 2 containing the silicon-based impact resistance improver D having a small proportion of the rubber component (silicone rubber) of 33% by mass has a large number average particle size of the improver D of 30 μm, and the rubber Since the glass transition point of the component is as low as −125 ° C., the Charpy impact strength at 23 ° C. and 0 ° C. satisfies the target value even when the ratio of the rubber component is as small as 33% by mass, but the Charpy impact at −20 ° C. The strength is as small as 3.62 kJ / m ² and the target value cannot be satisfied. From these facts, in order to obtain a vinyl chloride resin molded article having good Charpy impact strength in a low temperature range around -20 ° C., an impact resistance improver in which the proportion of the rubber component exceeds 50% by mass is used. I know you need to do that.

In addition, the test piece of Comparative Example 3 containing an acrylic impact resistance improver E having a rubber component of butyl acrylate rubber having a glass transition point of −54 ° C. as an impact resistance improver is a rubber component of the impact resistance improver. Is 90%, the Charpy impact strength at 23 ° C meets the target value, but the glass transition point of the rubber component is -54 ° C, so the Charpy impact strength at 0 ° C and -20 ° C is each 4.04kJ ^/ m 2, smaller and 3.234kJ / ^{m 2,} can not meet the target values. From this, in order to obtain a vinyl chloride resin molded article having good Charpy impact strength in a low temperature range of 0 ° C. or lower, an impact resistance improver having a rubber component having a glass transition point of −55 ° C. or lower is used. I know you need to do that.

  Further, the test piece of Comparative Example 2 containing the silicon-based impact resistance improver D satisfies the target value of Charpy impact strength at −20 ° C. because the ratio of the rubber component of the impact resistance improver is small. However, as with the test pieces of Example 1 and Example 2, FPI and SDI cleared the acceptance criteria of the flame retardancy test (FMRC), and from this, the rubber component and polymethyl methacrylate were added. The copolymerized impact modifier may reduce the flame retardancy of the molded article, as long as the impact modifier is contained within the content range of the present invention, whether the rubber component is large or small. I understand that there is no.

[Example 3]
The chlorination degree is 64.5% by mass, the polymerization degree is 670, and the post-chlorination vinyl chloride resin is 100 parts by mass. A basic composition containing 0.5 parts by mass of an ester lubricant, 2.0 parts by mass of an acrylic lubricant, and 0.6 parts by mass of titanium oxide as a filler is used as a basic composition. 4 types of vinyl chloride resin molded products containing 6 parts by mass, 8 parts by mass, 10 parts by mass and 15 parts by mass of MBS impact resistance improver A, respectively, and different contents of MBS impact resistance improver A A test piece was prepared.

  Similarly, 6 parts by mass, 8 parts by mass, 10 parts by mass, and 15 parts by mass of the silicon-based impact resistance improver B are contained in the basic composition, respectively. Four different types of vinyl chloride resin molded specimens were prepared. Similarly, the MBS impact resistance improver C was added to the above basic composition in an amount of 6 parts by mass, 8 parts by mass, 10 parts by mass, 15 parts, respectively. Four kinds of vinyl chloride resin molded specimens containing different parts of MBS impact resistance improver C were prepared, and the above silicon composition was improved in the same manner. 6 parts by weight, 8 parts by weight, 10 parts by weight, and 15 parts by weight of the agent D were prepared, and four types of vinyl chloride resin molded specimens having different contents of the silicon-based impact resistance improver D were prepared. Similarly, the above-mentioned acrylic 6 parts by weight, 8 parts by weight, 10 parts by weight, and 15 parts by weight of the improving agent E are prepared, and four kinds of test pieces of vinyl chloride resin molded bodies having different contents of the acrylic impact resistance improving agent E are produced. did.

  About each said test piece, it carried out similarly to Example 1, and measured the Charpy impact strength in 23 degreeC, 0 degreeC, and -20 degreeC. The results are shown in Table 2 below.

  From Table 2, it can be seen that the Charpy impact strengths of 23 ° C., 0 ° C., and −20 ° C. increase as the content of the impact modifier increases in all the test pieces. The MBS impact modifier A (a copolymer of styrene butadiene rubber and polymethyl methacrylate, having a number average particle size of 0.19 μm, a rubber component ratio of 70% by mass, and a glass transition of the rubber component. A test piece containing a point of −58 ° C.) and the above-described silicon-based impact modifier B (a copolymer of silicon rubber and polymethyl methacrylate having a number average particle size of 0.30 μm, When the content of the impact modifier is 6 parts by mass, the test piece containing 90% by mass of the rubber component and the glass transition point of the rubber component of −125 ° C. is 23 ° C. However, any Charpy impact strength of 0 ° C. and −20 ° C. cannot satisfy the target value, but it can be seen that the target values are all satisfied when the content is 8 parts by mass, 10 parts by mass, and 15 parts by mass. This confirms that it is necessary to contain 8 to 15 parts by mass of an impact resistance improver in order to exhibit good impact resistance from room temperature to low temperatures.

  On the other hand, the test piece containing the MBS impact resistance improver C has a ratio of styrene butadiene rubber as low as 50% by mass, and therefore the content of the impact resistance improver C is 6 parts by mass and 8 parts by mass. In either case of 10 parts by mass or 15 parts by mass, the target value of Charpy impact strength cannot be satisfied. The test piece containing the silicon-based impact resistance improver D has a small rubber component ratio of 33% by mass although the glass transition point of silicon rubber is as low as −125 ° C. When the content of the agent D is 6 parts by mass and 8 parts by mass, the target value of Charpy impact strength at 23 ° C. and 0 ° C. cannot be satisfied, and the target value of Charpy impact strength at −20 ° C. is 6 parts by mass, 8 parts by mass or 10 parts by mass cannot be satisfied. Furthermore, since the test piece containing the acrylic impact resistance improver E has a glass transition point of butyl acrylate rubber of −54 ° C., the content of the impact resistance improver is 6 parts by mass, 8 parts by mass, In either case of 10 parts by mass or 15 parts by mass, the target value of Charpy impact strength in a low temperature range of −20 ° C. cannot be satisfied, and the content is 23 ° C. when the content is 10 parts by mass and 15 parts by mass. The Charpy impact strength target value is satisfied, and when the content is 15 parts by mass, the Charpy impact strength target value of 0 ° C. is only satisfied. From this, in order to increase the impact resistance from room temperature to low temperature, the ratio of the rubber component of the impact modifier is over 50% by mass, and the glass transition point of the rubber component is −55 ° C. or less. It turns out that it is necessary.

Claims (5)

  A vinyl chloride resin molded product having a chlorine ratio of 50 to 64% by mass in the organic component in the molded product, wherein a rubber component having a glass transition point of −55 ° C. or less and a polymethyl methacrylate component are copolymerized. An impact resistance improver is contained in an amount of 8 to 15 parts by mass with respect to 100 parts by mass of the vinyl chloride resin.   2. The vinyl chloride resin molded article according to claim 1, wherein a ratio of the rubber component in the impact modifier is more than 50% by mass and 95% by mass or less.   The vinyl chloride resin molded article according to claim 1 or 2, wherein the impact resistance improver has a number average particle diameter of 0.10 to 0.50 µm.   The vinyl chloride according to any one of claims 1 to 3, wherein the rubber component is any one of styrene butadiene rubber, silicon rubber, and butyl acrylate rubber having a glass transition point of -55 ° C or lower. Resin molded product. Charpy impact strength at 23 ° C. measured according to JIS K 7111-1 is 7 kJ / m ² or more, Charpy impact strength at 0 ° C. measured according to JIS K 7111-1 is 5 kJ / m ² or more, The Charpy impact strength at −20 ° C. measured according to JIS K 7111-1 is 4 kJ / m ² or more, and the flame retardance index FPI measured based on the flame retardant test (FMRC) of FM4910 is 6 or less, The vinyl chloride resin molded article according to any one of claims 1 to 4, wherein the smoke index SDI is 0.4 or less.