JPS5928342B2 - Impact resistant vinyl chloride resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to impact resistant vinyl chloride resin compositions.

Specifically, the present invention relates to an impact-resistant hard vinyl chloride resin composition that is easy to prepare, inexpensive, exhibits little deterioration in other physical properties, and has excellent fluidity. Conventionally, as a general method to improve the impact strength of hard vinyl chloride resin molded products,
Methyl methacrylate/butadiene/vinyl chloride resin
Impact modifiers such as styrene copolymers and chlorinated polyethylene have been added.

However, while such improvement methods can improve impact strength, physical properties such as tensile strength, softening temperature, and hardness
The impact modifier decreases as the amount of impact modifier added increases, and there is a drawback that the effect of improving impact strength is not sufficient when added in small amounts that cause little deterioration of these physical properties. Moreover, impact modifiers are generally more expensive than vinyl chloride resins, resulting in higher product costs. Furthermore, various other proposals for improving the impact resistance of vinyl chloride resins have been made, but all of them have advantages and disadvantages, and at present no one has been found that is fully satisfactory. The present inventors have conducted various studies in order to improve the impact resistance of vinyl chloride resin easily, economically, and without impairing other physical properties by simple means. This invention has been achieved.

The impact-resistant vinyl chloride resin composition of the present invention comprises a suspension polymerized vinyl chloride resin with a polymerization degree of 400 to 1000, a polymerization degree of 4
Contains three components: a vinyl chloride resin selected from bulk polymerized vinyl chloride resins with a degree of polymerization of 800 to 1,000 and mixtures of these resins, (B) an emulsion polymerized vinyl chloride resin with a degree of polymerization of 800 to 2,000, and (C) an impact modifier. Then, the blending ratio of these three components is the weight blending ratio of the formula ^/old) (97-30)/(3-70
) and formula (C)/[^-HB] weight blending ratio ■(3~
25)/100.

Regarding the suspension polymerized vinyl chloride resin and bulk polymerized vinyl chloride resin 8 in the present invention, either one of them may be used alone or both may be used in combination.

Both of these vinyl chloride resins have a polymerization degree of 400 to 1,000. If the degree of polymerization is less than 400, mechanical properties such as impact resistance will be low, and if the degree of polymerization exceeds 1000, moldability will be poor in hard compounds, and there will be no noticeable improvement in physical properties. I can't do it. Moreover, as the emulsion polymerized vinyl chloride resin (B) in the present invention, one having a degree of polymerization in the range of 800 to 2000 is used.

If this degree of polymerization is less than 800, the impact strength will not be sufficiently improved when mixed with the resin (4), and if this degree of polymerization is less than 200,
If it exceeds 0, the compatibility with the resin (4) tends to decrease, which is not preferable. The suspension polymerized vinyl chloride resin, bulk polymerized vinyl chloride resin, and emulsion polymerized vinyl chloride resin in the present invention may all be a homopolymer of vinyl chloride, or may be a homopolymer of vinyl chloride and a relatively small amount of other monomers. There is no problem even if it is a copolymer with

Representative examples of such copolymers include vinyl chloride/vinyl acetate copolymers, vinyl chloride/alkyl vinyl ether copolymers, vinyl chloride/ethylene copolymers, and vinyl chloride/propylene copolymers. The impact modifier (C) in the present invention is a general term for organic polymer modifiers that can improve the impact resistance of vinyl chloride resin by blending it with vinyl chloride resin, and generally has elastic rubber-like properties. A polymer having the following is used.

For example, methyl methacrylate/butadiene/styrene copolymer (referred to as [MBS]), acrylonitrile/
Butadiene/styrene copolymer (referred to as "ABS")
, acrylonitrile/butadiene rubber (referred to as "NBR"), lower alkyl acrylate polymers (e.g. copolymers of lower alkyl acrylate and methyl methacrylate and/or styrene), chlorinated polyethylene, chlorosulfonated polyethylene, ethylene/ Examples include vinyl acetate copolymers and vinyl chloride grafted products of ethylene/propylene binary or ternary copolymers.
These impact modifiers can be used alone or in combination of two or more. In the present invention, the above three components (A), (B) and 0 are blended in a proportion that satisfies both of the following two formulas.

Weight blending ratio of (A)AB)=(97~30)/(3~
70) Polymerization blending ratio of (0/[(A)+B)] = (3~
If the blending ratio of 25)/100(B) is too low, the impact improving effect cannot be obtained, and if the blending ratio is too high, (B) itself has poor thermal stability, so the thermal stability of the composition Stability deteriorates.

For this purpose, the weight blending ratio of (.A)/(B) is selected within the above range. The preferred range of the blending ratio is (95-70)/(5-30). Also,
The weight blending ratio of (O to [(4)+(B)] is 3%
If it is less than 25%, the impact improvement effect will not be sufficient, and if it exceeds 25%, the tensile strength, softening temperature, hardness, etc. will decrease, and the original properties of the hard vinyl chloride resin will be impaired.

The preferred range of the same blending ratio is (5 to 15)/1
It is 00.

The impact-resistant vinyl chloride resin composition of the present invention can be obtained by blending the above three components in a ratio that satisfies the above blending conditions, and all three components can be blended in powder form.

In addition to these three components, the resin composition of the present invention may further contain other components. example is,
Stabilizers, lubricants, radiation absorbers, fillers, processing aids (for example, methyl methacrylate processing aids), etc. can be blended. The impact-resistant vinyl chloride resin composition of the present invention is thus prepared by blending the above-mentioned three components and other components that may be further blended as necessary in proportions that satisfy the above-mentioned blending ratio. Moreover, since the three components can be easily blended even in the form of powder, conventional equipment and means can be used as they are, and no special ingenuity is required for the blending.

Furthermore, all three components are easily and inexpensively available. Therefore, the resin composition of the present invention can be prepared very advantageously technically, industrially and economically. In particular, the composition of the present invention may contain impact modifiers other than impact modifiers containing butadiene components such as MBS and ABS (for example, chlorinated polyethylene, ethylene monovinyl acetate copolymer, lower alkyl acrylate polymer, ethylene-propylene type polymer). This is particularly useful when using copolymers (copolymers, etc.). That is, although MBS, ABS, etc. containing a butadiene component have a considerable impact improving effect by themselves, they have the disadvantage of poor weather resistance. On the other hand, impact modifiers that do not contain butadiene components have good weather resistance, but impact strength does not improve sufficiently when used in small amounts that do not impair the inherent properties of hard vinyl chloride resin. Therefore, if an impact modifier with excellent weather resistance that does not contain a butadiene component is used as the (O component) of the composition of the present invention, the impact strength can be greatly improved with a small amount. Moreover, the resin composition of the present invention can be easily added by a method similar to the conventional processing method of this type of vinyl chloride resin, and has good fluidity, It can be processed more favorably than resin-based materials.

For example, injection molding produces impact-resistant injection molded products such as pipe fittings, TV cases, and taller cases, while extrusion molding produces impact-resistant extrusion molded products such as various industrial plates, sheets, and irregularly shaped products. Furthermore, various impact-resistant calender press molded products can be easily produced by the calender method. A molded article obtained by molding the resin composition of the present invention has significantly better impact resistance than a conventional hard vinyl chloride resin molded article.

In addition, other physical properties such as tensile strength, softening point, and hardness of the molded product are almost comparable to those of ordinary hard vinyl chloride resin molded products. It has most of its physical properties intact. Example 1 As shown in Table 1 below, suspension-polymerized vinyl chloride resins and emulsion-polymerized vinyl chloride resins with various degrees of polymerization were used, and chlorinated polyethylene (trade name of Showa Denko Co., Ltd., Elasrene 351A) and Dioctyltin malate polymer was blended into various resin compositions.

Each of these resin compositions was heated to 180°C using a roll.
After kneading for 0 minutes, a test piece was prepared by hot pressing at a temperature of 18°C for 10 minutes.

Table 1 shows the results of a Schalpy test (for a 411 m thick plate) and a tensile test (for a 2 nm thick plate) for each test piece. As is clear from the results in Table 1, the impact strength of suspension polymerized vinyl chloride resin increases as the degree of polymerization increases, but the tensile strength decreases (see Stones 1 to 5).

Furthermore, even if suspension polymerized vinyl chloride resins with different degrees of polymerization are mixed together, the impact strength does not change much (for example,
Please compare ni 6 to 8. ). However, when an emulsion polymerized vinyl chloride resin is blended with a suspension polymerized vinyl chloride resin, the impact strength increases significantly, and the tensile strength does not decrease at all (see Examples 9 to 11). Furthermore, even if a suspension-polymerized vinyl chloride resin and an emulsion-polymerized vinyl chloride resin are blended, those that do not contain any chlorinated polyethylene have extremely low impact strength (see ▲12).
. In addition, the polymers Nos. 6 to 12 were blended so that the average degree of polymerization of the polymers was arithmetically 800. Example 2 Bulk polymerized vinyl chloride resin with a degree of polymerization of 800 and a degree of polymerization of 200
100 parts by weight of vinyl chloride resin blended with emulsion-polymerized vinyl chloride resin of
By weight, 2 parts by weight of dioctyltin malate polymer and 1 part by weight of dioctyltin-S,s'-bis(isooctylmercaptoacetate) were blended to prepare various vinyl chloride resin compositions. "Example composition".

). For comparison, various vinyl chloride resin compositions were prepared in the same manner as above except that no chlorinated polyethylene was blended (these are referred to as "comparative compositions").

). Using the above Example compositions and Comparative Example compositions, after molding under the same conditions as in Example 1, a Schalpi test was conducted, and the results shown in FIG. 1 were obtained.

That is, the impact strength of the example composition containing chlorinated polyethylene (impact modifier) increases rapidly as the blending ratio of emulsion polymerized vinyl chloride resin increases, whereas the comparative example composition containing no chlorinated polyethylene There is almost no change in impact strength even when the blending ratio of emulsion polymerized vinyl chloride resin is increased. This indicates that in the resin composition of the present invention, the emulsion polymerized vinyl chloride resin and the chlorinated polyethylene have a synergistic effect on increasing impact strength. Example 3 Molding was carried out under the same conditions as in Example 1 using resin compositions with various formulations shown in Table 2 below.

When the molded article obtained was subjected to the same Schalpy impact test and tensile test as in Example 1, the results shown in Table 2 were obtained.

As is clear from the results in Table 2, even if the type of impact modifier is changed, the impact strength can be increased in the same way, and the tensile strength hardly decreases.

Example 4 Various vinyl chloride resin compositions having the formulations shown in Table 3 below were used, and after kneading for 10 minutes using a roll heated to 180°C, using a Koka type flow tester,
When the fluidity was measured at a temperature of 200° C., the results shown in FIG. 2 were obtained.

By blending emulsion-polymerized vinyl chloride resin with suspension-polymerized vinyl chloride resin (when compared with the same arithmetic average degree of polymerization), fluidity is significantly improved (▲3 and boiled 1, boiled 4 and ▲2) (Please compare each.)

[Brief explanation of drawings]

FIG. 1 is a drawing showing the relationship between the blending ratio of vinyl chloride resin in the resin composition described in Example 2 and the Sharpie impact strength of the molded article. FIG. 2 is a diagram showing the relationship between the apparent shear rate and apparent shear stress of the resin composition described in Example 4 (Table 3), that is, the fluidity. Indicates the experiment number.

Claims (1)

[Scope of Claims] 1 (A) A vinyl chloride resin selected from suspension polymerized vinyl chloride resins with a polymerization degree of 400 to 1,000, bulk polymerized vinyl chloride resins with a polymerization degree of 400 to 1,000, and mixtures of these resins, (B) ) An emulsion-polymerized vinyl chloride resin with a polymerization degree of 800 to 2000, and (C) an impact modifier are blended, and the blending ratio of these three components is the polymerization blending ratio of formula (A)/(B) = ( 97-30)/(3
~70) and the polymerization blending ratio of formula (C)/[(A)+(B)]=(3-25)/100. Vinyl resin composition.