JPH0249013A - Heat-resistant vinyl chloride resin - Google Patents

Abstract

PURPOSE:To provide the subject resin having excellent heat-resistance and impact-resistance by radically polymerizing vinyl chloride monomer in the presence of a methyl methacrylate.N-substituted maleimide copolymer. CONSTITUTION:The objective resin is obtained by radically polymerizing monomers comprising mainly vinyl chloride in the presence of a methyl methacrylate.N-substituted maleimide copolymer comprising mainly methyl methacrylate. The copolymer is preferably composed from 50-80wt.% of methyl methacrylate component, 10-50wt.%, preferably 20-40wt.%, of an N-substituted maleimide component and 0-10wt.% of other monomer components.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heat-resistant vinyl chloride resin with good impact resistance.

(Prior Art) Vinyl chloride resin has high rigidity and tensile strength, and is excellent in flame retardancy, weather resistance, and chemical resistance, so it is widely used for pipes, plates, films, sheets, and the like. However, vinyl chloride resin has a low softening point and lacks heat resistance. For example, 7
It softens and undergoes thermal deformation at temperatures between 0 and 80°C, so it cannot be used at higher temperatures.

As a method of improving the heat resistance of vinyl chloride resin, it has been proposed to melt-knead a copolymer consisting of a methyl methacrylate component, an N-substituted maleimide component, and an aromatic vinyl compound to a vinyl chloride resin ( Unexamined Japanese Patent Publication 1986-46
(See Publication No. 249).

However, in this method, when the vinyl chloride resin and the above-mentioned copolymer are melt-mixed, the resin tends to be dehydrochlorinated and colored yellow, so it is difficult to ensure that the above-mentioned copolymer is sufficiently uniformly mixed into the resin. There are problems in that it cannot be kneaded, heat resistance is insufficiently improved, and impact resistance is reduced.

(Problems to be Solved by the Invention) The present invention solves the above problems, and its purpose is to provide a heat-resistant vinyl chloride resin with good impact resistance.

(Means for Solving the Problems) The heat-resistant vinyl chloride resin of the present invention is made of vinyl chloride as a main component in the presence of a methyl methacrylate/N-substituted maleimide copolymer containing methyl methacrylate as a main component. It is obtained by radical polymerization of the monomer, thereby achieving the above object.

In the present invention, the methyl methacrylate/N-substituted maleimide copolymer containing methyl methacrylate as a main component generally contains 50 to 80% by weight of the methyl methacrylate component and the N-substituted maleimide component. is 10-5
0% by weight, preferably 20 to 40% by weight, and 0 to 10% by weight of other monomer components.

As the N-substituted maleimide, the alkyl group has 1 carbon number
-4 N-alkylmaleimide, N-phenylmaleimide, N-chlorophenylmaleimide, N-cyclohexylmaleimide, etc. are preferably used. Further, as other monomers mentioned above, styrene, α-alkylstyrene, halogenated styrene, acrylonitrile, maleic anhydride, etc. are used depending on the purpose.

When the methyl methacrylate component is less than 50% by weight, transparency decreases, and when it exceeds 80% by weight, heat resistance decreases. Moreover, if the N-substituted maleimide component is less than 10% by weight, heat resistance will decrease, and if it exceeds 50% by weight, processability will decrease. Furthermore, if the amount of other monomer components exceeds 10% by weight, processability may be impaired.

The above-mentioned methyl methacrylate/N-substituted maleimide copolymer can be produced by suspension polymerization using a known radical polymerization initiator.
It can be produced by a commonly used polymerization method such as a solution polymerization method.

In this case, the average molecular weight (measured by gel permeation chromatography) of the resulting copolymer is generally from 1000 to
It is preferable to adjust it to a range of 50,000.

The heat-resistant vinyl chloride resin of the present invention can be obtained by radical polymerizing a monomer containing vinyl chloride as a main component in the presence of the methyl methacrylate/N-substituted maleimide copolymer.

Monomers containing vinyl chloride as a main component include vinyl chloride alone or vinyl chloride with (meth)acrylic ester,
A mixture of other monomers such as vinyl acetate, vinyl alcohol, vinyl ether, styrene, ethylene, and propylene in an amount of 10% by weight or less depending on the purpose is used.

Radical polymerization, for example, dilauroyl peroxide,
In order to enhance the grafting effect, such as isobutyryl peroxide, a known radical polymerization initiator consisting of an organic peroxide with a high hydrogen abstraction effect is used, and a suspension polymerization method in an aqueous medium such as water or alcohol, tetrahydrofuran, or methyl ethyl chloride is used. It is carried out by a solution polymerization method in an organic solvent such as -.

In this case, the polymerization temperature is generally adjusted to a range of 30 to 80°C. Generally, the methyl methacrylate/N-substituted maleimide copolymer component in the resin is 5 to 50% by weight, preferably 10 to 40% by weight, the vinyl chloride component is 50 to 85% by weight, and the other monomers are 5 to 50% by weight, preferably 10 to 40% by weight. Body composition is 0 to 10% by weight.

If the vinyl chloride component is less than 50% by weight and the methyl methacrylate/N-substituted maleimide copolymer component exceeds 50% by weight, the original characteristics of the vinyl chloride resin will deteriorate and the processability will deteriorate. descend. In addition, when the vinyl chloride component exceeds 85% by weight and the methyl methacrylate/N-substituted maleimide copolymer component falls below 5% by weight,
Heat resistance decreases. Furthermore, if the amount of other monomers exceeds 10% by weight, there is a risk that the original characteristics of the vinyl chloride resin will be impaired.

The composition of the heat-resistant vinyl chloride resin of the present invention is as described above, but when producing molded objects such as vibrators, plates, films, and sheets using this resin, heat stabilizers, lubricants,
Various compounding agents commonly used in vinyl chloride resins, such as processing aids, impact modifiers, light stabilizers, colorants, antistatic agents, and fillers, are added as necessary.

(Function) As in the present invention, when a monomer containing vinyl chloride as a main component is radically polymerized in the presence of a methyl methacrylate/N-substituted maleimide copolymer containing methyl methacrylate as a main component, the above-mentioned A resin in which the copolymer is uniformly dispersed and in which vinyl chloride is mainly graft-polymerized to the main chain of the copolymer molecule can be obtained.

(Example) Examples and comparative examples of the present invention are shown below.

(A) Production of methyl methacrylate/N-substituted maleimide copolymer 3! 1.52 g of methanol was put into a 4-tube flask, and 300 g of methyl methacrylate and 100 g of N-phenylmaleimide were added thereto, and the internal temperature was raised to 50°C.

After N-phenylmaleimide was completely dissolved, the inside of the flask was filled with nitrogen, and 4 g of t-butylperoxyneodecanoate was added as a polymerization initiator, and copolymerization was carried out for 8 hours.

The obtained granular coelectric material has a methyl methacrylate component of 7
5% by weight, N-phenylmaleimide component is 25% by weight, and the average molecular 1i (measured by GPC) is about 500.
It was 0.

(B) Production of heat-resistant vinyl chloride resin 41 ion-exchanged water, 7.5 g of partially saponified polyvinyl alcohol, and 3 g of dilauroyl peroxide as a polymerization initiator were placed in a 10-f pressure-resistant polymerization vessel equipped with a stirrer. The methyl methacrylate/N-phenylmaleimide copolymer obtained in ) was pulverized into powder, 200 g of this powdered copolymer was added and dispersed, and the inside of the vessel was evacuated.

Then, add 1500 g of vinyl chloride and bring the internal temperature to 65°.
C. and polymerization was carried out for 8 hours.

The obtained resin consisted of 20% by weight of the methyl methacrylate/N-phenylmaleimide copolymer component and 80% by weight of the vinyl chloride component, and had an average degree of polymerization equivalent to 1000 according to JIS K-6721.

(C) Evaluation of physical properties of heat-resistant vinyl chloride resin To 100 parts by weight of the resin obtained in (B) above, 2.0 parts by weight of dimethyl tin mercapto and 0.3 parts by weight of ester wax were added. The mixed powder was mixed in a mixer for 3 minutes at 190°C, and the mixed powder was kneaded for 5 minutes with a roll at 190°C to obtain a sheet.The sheets were stacked and heated under pressure for 5 minutes in a press that maintained the temperature at 190°C. A desired molded plate was obtained.This pressed plate was used as a sample and heat resistance (ASTM D-648
heat distortion temperature) and impact resistance (JIS K-711
Charpy impact value according to No. 1) was measured. The results are shown in Table 1.

(A) Production of methyl methacrylate/N-substituted male/imide copolymer Place 1.52 g of ion-exchanged water in a 4-tube flask in step 31.
Furthermore, add 330 g of methyl methacrylate, 50 g of N-cyclohexylmaleimide, 20 g of styrene, and add L
-Putyl baroxyneodecane) 4g and 50
Copolymerization was carried out at °C for 8 hours.

The obtained granular copolymer contained 83% by weight of methyl methacrylate component and 12% by weight of N-cyclohexylmaleimide component.
% by weight, the styrene component is 5% by weight, and the average molecular weight is 1
(measured by CGPC) was about 10,000.

(B) Manufacture of heat-resistant vinyl chloride resin 6.
I! ,, 3 g of isobutyryl peroxide was added, and the methyl methacrylate/N-cyclohexylmaleimide/styrene copolymer obtained in step (A) was ground into a powder, and 300 g of this powder copolymer was added. was added and dispersed, and the inside of the vessel was evacuated. Thereafter, 1500 g of vinyl chloride monomer was added, the internal temperature was raised to 50°C, and polymerization was carried out for 8 hours.

The resulting resin contained 37% by weight of methyl methacrylate/N-cyclohexylmaleimide/styrene copolymer component, and had an average degree of polymerization of 800.

(C) Evaluation of physical properties of heat-resistant vinyl chloride resin Using the resin obtained in (B) above, heat resistance and impact resistance were measured in the same manner as in (C) of Example 1. The results are shown in Table 1.

In (B) of Example 1, methyl methacrylate N-
The heat resistance and impact resistance were measured in the same manner as in Example 1 (B) and (C) except that 200 g of the phenylmaleimide copolymer was changed to 400 g. The result is the first
Shown in the table.

Methyl methacrylate N- obtained in Example 1 (A)
Phenylmaleimide copolymer 20! i amount part, polymerization degree 1
The mixture was melt-kneaded with 80 parts by weight of polyvinyl chloride resin No. 040 to produce a heat-resistant vinyl chloride resin composition. Heat resistance and impact resistance were measured in the same manner as in Example 1 (C) except that this resin composition was used. The results are shown in Table 1.

Methyl methacrylate N- obtained in (A) of Example 2
A heat-resistant vinyl chloride resin composition was prepared by melt-kneading 37 parts by weight of a cyclohexylmaleimide-styrene copolymer with 63 parts by weight of a polyvinyl chloride resin having a degree of polymerization of 1040. Except for using this resin composition, (
Heat resistance and impact resistance were measured in the same manner as C). The results are shown in Table 1.

Table 1 (blank below) (Effects of the invention) As mentioned above, the heat-resistant vinyl chloride resin of the present invention contains methyl methacrylate/N, whose main component is methyl methacrylate.
Since the monomer containing vinyl chloride as a main component is graft-polymerized to the -substituted maleimide copolymer, the copolymer is uniformly dispersed and is strongly bonded to the vinyl chloride resin.

Therefore, compared to conventional compositions in which the above-mentioned copolymer is melt-kneaded with vinyl chloride resin, it has a remarkable effect of improving heat resistance and impact resistance.

Claims (1)

[Claims] 1. Heat-resistant vinyl chloride resin obtained by radical polymerization of a monomer whose main component is vinyl chloride in the presence of a methyl methacrylate/N-substituted maleimide copolymer whose main component is methyl methacrylate. .