JPH04153247A - Heat-and impact-resistant vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in heat resistance, impact resistance and moldability by mixing a vinyl chloride resin with a polycarbonate resin and polymethyl methacrylate. CONSTITUTION:100 pts.wt. in total of 65-95 pts.wt. vinyl chloride resin of an average degree of polymerization of 700-1800 and 35-5 pts.wt. polycarbonate resin of a molecular weight of 10000-50000 is mixed with 4-25 pts.wt. polymethyl methacrylate of a molecular weight of 1000-1000000 and optionally 3-10 pts.wt. impact modifier (e.g. ABS), a stabilizer (e.g. white lead), a lubricant, etc.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a vinyl chloride resin composition with improved heat resistance and impact resistance, and this resin composition has good fluidity when melted and has good moldability. It has good properties and can be molded into any shape by extrusion molding, injection molding, etc., so it is useful as a molding material for various things including pipes.

[Prior Art] Vinyl chloride resins are inexpensive, have excellent physical properties, and are easily molded, so they are widely used for various purposes. However, it has the disadvantage of poor heat resistance and impact resistance, so many improvement studies are underway to improve the heat resistance. A method has been proposed in which a heat resistance improver such as polycarbonate resin is blended into the resin.

However, in the former post-chlorination method, chlorination not only deteriorates molding processability but also tends to cause thermal decomposition, so chlorination naturally has its limits. Heat resistance cannot be sufficiently increased under these conditions.

Furthermore, in the latter blending method, the heat resistance improving effect as expected cannot be obtained because the heat resistance improver and the vinyl chloride resin have poor compatibility. In addition, in order to increase the compatibility between the polycarbonate resin and the vinyl chloride resin that are blended as a heat resistance improver, a method of using a styrene-methyl methacrylate block copolymer as a compatibilizer (JP-A-1-2013 No. 210450) has also been proposed, but it does not necessarily provide satisfactory heat resistance. Moreover, when a polycarbonate resin is blended, a problem arises in that the tensile elongation rate decreases and the impact resistance becomes extremely poor.

In addition, MBS is used to improve the impact resistance of vinyl chloride resin.
Although blending resins has been practiced for quite some time, no effect on improving heat resistance can be expected from MBS resins.

[Problems to be Solved by the Invention] The present invention has been made focusing on the above-mentioned circumstances, and its purpose is to blend a polycarbonate resin as a heat resistance improver among the heat resistance improving methods. The aim is to provide a vinyl chloride resin that improves heat resistance by increasing its compatibility, prevents the drop in impact resistance that is considered a drawback, and has good moldability. be.

[Means for Solving the Problems] The composition of the resin composition according to the present invention that can solve the above problems is as follows: Vinyl chloride resin: 65 to 95 parts by weight Polycarbonate resin: 35 to 5 parts by weight Polymethyl methacrylate : It has the gist that it contains 4 to 25 parts by weight based on the total of 100 parts by weight of the above-mentioned vinyl chloride resin and polycarbonate resin.

[Function] Vinyl chloride resin is the most common vinyl chloride resin used as the base of the resin composition according to the present invention, but in addition, small amounts of vinylidene chloride, vinyl acetate, (meth)acrylic acid ester, and styrene are used. It may be copolymerized with copolymerizable monomers such as, or it may be post-chlorinated in some cases to improve heat resistance.

The molecular weight is appropriately selected depending on the required characteristics of the molded product, but considering moldability, physical properties, heat resistance, etc., the most common one is an average degree of polymerization (di) of 700 to 1800, more preferably 900 to 1500. It is within the range of . Further, when using a post-chlorinated vinyl chloride resin, it is preferable to use one having a degree of chlorination of about 70% or less in order to ensure excellent heat decomposition resistance, impact resistance, and moldability.

Next, the polycarbonate resin is blended as a heat resistance improver, and all conventionally known resins can be used, including those in which aromatic rings are converted to Br, branched polycarbonates, etc. However, if the molecular weight becomes too large, Even if a compatibilizing agent is used in combination, the compatibility may not be sufficiently improved, and conversely, if the molecular weight is too small, a satisfactory effect of improving heat resistance will not be exhibited. Preferably 2000
It is preferable to use a value in the range of 0 to 40,000.

The blending amounts of the vinyl chloride resin and polycarbonate resin are 65 to 95 parts by weight for the former and 35 to 5 parts by weight for the latter.
Parts by weight, more preferably the former should be in the range of 70 to 9031 parts by weight and the latter should be in the range of 30 to 10 parts by weight,
If the blending amount of the vinyl chloride resin is less than the above range, the inherent characteristics of the vinyl chloride resin, especially moldability, will not be effectively exhibited, and the cost will increase.On the other hand, if it exceeds the above range, the heat resistance If the amount of polycarbonate resin blended as a property improver becomes insufficient, the effect of improving heat resistance as intended by the present invention cannot be obtained.

As mentioned above, the polycarbonate resin has poor compatibility with the vinyl chloride resin, and simply blending these resins will not produce the effect of improving heat resistance as intended by the present invention.
Furthermore, the tensile elongation rate decreases, resulting in extremely poor impact resistance, and furthermore, the moldability is also extremely poor due to lack of fluidity when melted. Furthermore, as mentioned above, even when a styrene-methyl methacrylate block copolymer is used as a compatibilizer, it is not possible to obtain a satisfactory effect of improving heat resistance and moldability, and there is also a decrease in impact resistance. Therefore, the present inventors have developed a method that not only has an excellent effect of improving heat resistance and moldability, but also can prevent the decrease in impact resistance caused by the blending of polycarbonate resin. The effects of adding various compounds were investigated for the purpose of searching for the three components.

As a result, it was surprisingly confirmed that polymethyl methacrylate (PMMA), which is well known as a familiar polymer, has excellent effects that meet the above objectives. In other words, by blending an appropriate amount of PMMA with a polycarbonate resin into a vinyl chloride resin, it is possible to effectively increase heat resistance without impeding moldability, and also prevent a decrease in impact resistance, which has been a problem in the past. This makes it possible to obtain a resin composition that also has a high level of impact resistance. However, in order to effectively exhibit these effects, 4 parts by weight or more of PMMA must be added to 100 parts by weight of the vinyl chloride resin and polycarbonate resin.
If the amount is less than 4 parts by weight, these effects will not be effectively exhibited.

However, if the amount exceeds 25 parts by weight, not only will no further heat resistance improvement effect be obtained, but the impact resistance and tensile elongation will decrease. The range was determined to be 5 to 25 parts by weight.

This PMMA has the effect of increasing impact resistance while acting as a compatibilizer for vinyl chloride resin and polycarbonate resin, and in order to effectively exhibit this effect, the preferable molecular weight is 1.000 to 1. ,000,
000, more preferably 10,000 to 100,00
0. However, if the molecular weight is too low, the heat resistance will be lowered, while if the molecular weight is too high, the compatibilizing effect will be poor, leading to the risk of deteriorating impact resistance and moldability. The PMMA component may also contain a small amount of other acrylic esters such as butyl acrylate and ethyl acrylate, butyl rubber, and the like.

Although the above three components constitute the four essential constituents of the present invention, it is of course possible to further include the following components as other components depending on the application.

Impact-strengthening agents have the effect of increasing the impact resistance of vinyl chloride-based resin molded products, such as MBS, ABS, chlorinated polyethylene (CPE), acrylic impact-strengthening agents, etc. By blending about 3 to 10 parts by weight with respect to the total of 100 parts by weight of the polycarbonate resin and the polycarbonate resin, even better impact resistance can be obtained.

The resin composition of the present invention has a high softening point and excellent heat resistance. Lead salt stabilizers such as acid lead, lead silicate, and silica gel coprecipitates Higher fatty acid stabilizers such as nistearic acid and its Ca and lead salts; triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite Stability can be further enhanced by adding a small amount of organic stabilizing aids such as phite, trinonylphenyl phosphite, etc., and ultraviolet absorbers such as salicylic acid esters, hydroxybenzophenones, and benzotriazole.

In addition to increasing the fluidity of the molten resin and improving its moldability, it also has the effect of increasing the surface smoothness of the molded product while preventing it from sticking to the molding die and improving its releasability.Higher fatty acids and their derivatives, Examples include natural or synthetic waxes.

Mie L Mainly has the effect of increasing the hardness, modulus, and bending rigidity of molded products, and contains calcium carbonate, kaolin, clay,
Examples include silica, diatomaceous earth, and carbon black.

Other Compounding Agents As compounding agents other than those mentioned above, colorants, flame retardants, IF antistatic agents, foaming agents, fungicides, etc. may be added as necessary.

[Example] Examples 1 to 8, L Examples 1 to 6 Chlorinated vinyl chloride resin (CPVC) (manufactured by Kanebuchi Chemical Co., Ltd.'H
727J: P = 1050) tf') Carho*-toi resin (PC) (trade name, manufactured by Idemitsu Petrochemical Co., Ltd., "TAFLON A-2200J: molecular weight 27,700), PMM
A (“Acrivet IRH-70” manufactured by Mitsubishi Rayon Co., Ltd.)
) and MBS resin (rB”rA 7 manufactured by Kureha Chemical Co., Ltd.
51J) and higher fatty acids and their salts (tribase; lead stearate Ca nistearate: powdered stearic acid = 1:1:1:0.5 mixture) as a stabilizer,
After uniformly heating and kneading these by the roll method at the ratio shown in Table 1, the mixture was heated to 15 m+oX 15 by the press method.
A test molded body of a+a+x 3.5o+m was created.

Also, for comparison, PMMA is omitted, or PMM
Test molded products were similarly prepared in which both A and the polycarbonate resin were omitted, or in which the blending composition was outside the specified range of the present invention.

Vicat softening point (load I
Kg value (2℃), Charpy impact value (Kg/cm
), tensile strength (g/cm') and tensile elongation (%)
was measured, and the results are shown in Table 1. From Table 1, the following can be considered.

Examples 1 to 8 satisfy the specified requirements of the present invention,
Both have higher Vicat softening points and excellent heat resistance than the comparative examples. In addition, all of these resin compositions showed less decrease in tensile elongation and Charpy impact value than Comparative Examples 2.3, etc., had a high level of impact resistance, and had good fluidity when melted. , and had excellent moldability.

On the other hand, Comparative Examples 1 to 6 lacked any of the requirements specified by the present invention as described below, and either the Vicat softening point or the Charpy impact value was insufficient.

Comparative Example 1: A product that only has an impact strengthener and a stabilizer added to vinyl chloride resin, and is different from polycarbonate resin and PM.
Since no MA was blended, the Vicat softening point was low and the heat resistance was insufficient.

Comparative Example 2.3 = Polycarbonate resin is blended, but PMMA is not blended, so not only is the heat resistance insufficient, but the Charpy impact value is also extremely low.
The moldability was also poor.

Comparative Example 4: The amount of PMMA blended was insufficient, and the compatibilization effect was insufficient, so the heat resistance improvement effect was somewhat insufficient, the impact properties were also low, and the moldability was not improved much.

Comparative Example 5: The amount of PMMA blended was too large, and the heat resistance improvement effect reached a plateau. The filF properties and tensile elongation are poor.

Comparative Example 6: The amount of polycarbonate resin blended is too large, and although the heat resistance is good, a considerable amount of PMMA
The impact properties and tensile elongation are very poor despite the fact that it contains

Stream side 9 to 12, Comparative examples 7 to 9 Vinyl chloride resin (p:
Sample molded bodies were prepared and performance tests were conducted in the same manner as in the above Examples and Comparative Examples, except that 1050) was used.

The blending composition and performance test results are collectively shown in Table 2, and almost the same trends as those obtained in Examples 1 to 8 and Comparative Examples 1 to 6 can be confirmed. That is, Examples 9 to 12 that meet the specified requirements of the present invention have a lower Vicat softening point,
High average values were obtained for both Charpy impact value and tensile strength, indicating that the material had excellent heat resistance and physical properties.

[Effects of the Invention] The present invention is configured as described above, and by blending an appropriate amount of PMMA with a polycarbonate resin into a vinyl chloride resin, the heat resistance improving effect of the polycarbonate resin is more effectively exhibited. At the same time, it is possible to provide a vinyl chloride resin composition which prevents a decrease in impact resistance caused by blending the polycarbonate resin and has good moldability.

Claims (1)

[Claims] Vinyl chloride resin: 65 to 95 parts by weight Polycarbonate resin: 35 to 5 parts by weight Polymethyl methacrylate: 4 to 4 parts by weight based on 100 parts by weight of the above vinyl chloride resin and polycarbonate resin
A heat-resistant and impact-resistant vinyl chloride resin composition containing 25 parts by weight.