JPH02175740A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in heat and impact resistances and processability by mixing a vinyl chloride polymer with a specified rubber-modified resin. CONSTITUTION:A rubber-modified resin is obtained by the two-stage graft polymerization of 100 pts.wt. monomer mixture comprising 5-35wt.% maleimide compound (a) (e.g. N-phenylmaleimide), 0-25wt.% alkyl (meth)acrylate (b) (e.g. methyl methacrylate), 3-30wt.% vinyl cyanide monomer (c) (e.g. acrylonitrile), and 45-92wt.% aromatic vinyl monomer (d) (e.g. styrene) in the presence of 4-40 pts.wt. rubber component (e) (e.g. polybutadiene) by a solution or bulk polymerization process so that the amount of component (a) polymerized may amount to 3-11wt.% of the monomer mixture polymerized in the first stage before phase inversion and the amount of component (a) polymerized may amount to 3-11wt.% in the second stage after phase inversion. 5-150 pts.wt. obtained resin is added to 100 pts.wt. vinyl chloride polymer of a degree of polymerization of desirably 600-2500.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to building materials such as pipes, roofing materials, window frames, electrical parts,
This invention relates to a vinyl chloride resin composition that has excellent heat resistance, impact resistance, and processability and is useful for various molded products such as automobile parts and miscellaneous goods.

[Conventional technology]

Vinyl chloride resin is widely used in various fields because it is inexpensive and has excellent physical and chemical properties, but it has the disadvantage of poor heat resistance and impact resistance, which limits its range of use. There is.

For this reason, many attempts have been made to improve the heat resistance and impact resistance of vinyl chloride resins. For example, a method of blending a rubber-modified resin obtained by graft polymerizing monomers such as methacrylic acid, maleic anhydride, maleimide compound, acrylonitrile, acrylic ester, and methacrylic ester is disclosed in JP-A-57-162745. No. 60-2487
No. 58, No. 61-143459, No. 61-16254
It is disclosed in various publications such as No. 3 and No. 62-57446.

[Problem to be solved by the invention]

However, most of the above-mentioned known blending methods use a combination of two types of rubber-modified resins with different monomer types, or use a rubber-modified resin together with a resin component that does not contain a rubber component. Perhaps due to the content of the rubber component or the type of monomer used, the heat resistance or impact resistance is still insufficient, so the use of vinyl chloride resins is being expanded. Moreover, it could never be said that the properties of heat resistance, impact resistance, and processability were all fully satisfactory.

In view of the above-mentioned current situation, the present invention aims to provide a vinyl chloride resin composition that has excellent processability inherent to vinyl chloride resins, as well as excellent heat resistance and impact resistance. The purpose is

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the present inventors have found that by blending a specific rubber-modified resin with a vinyl chloride resin, the properties of heat resistance, impact resistance, and processability can be improved. Having learned that an excellent vinyl chloride resin composition can be obtained, the present invention was completed.

That is, the present invention comprises: A) 100 parts by weight of a vinyl chloride polymer, B) 5 to 35 weight % of a maleimide compound, and an acrylic acid alkyl ester and/or a methacrylic acid alkyl ester in the presence of 4 to 40 parts by weight of a rubber component. 0 to 25% by weight, 3 to 30% vinyl cyanide monomer, and 45 to 45% vinyl aromatic monomer.
In the first step before phase inversion, 100 parts by weight of a monomer mixture consisting of 92% by weight is added by a solution or bulk polymerization method, and in the first step before phase inversion, the proportion of the maleimide compound in the polymerized monomer mixture is 3 to 11% by weight. 5 to 150 parts by weight of a rubber-modified resin obtained by two-step graft polymerization are blended so that the same proportion is in the range of 12 to 42 weight % in the second stage after phase inversion. This relates to a vinyl chloride resin composition.

[Structure and operation of the invention]

The vinyl chloride polymer that is component A used in the present invention is a homopolymer of vinyl chloride, vinyl chloride and ethylene,
Contains copolymers with propylene, vinyl acetate, etc., or copolymers of vinyl chloride with vinyl ethers, esters of acrylic acid or methacrylic acid, methacrylamide, acrylonitrile, maleimide compounds, etc.
Any production method such as bulk polymerization, suspension polymerization, emulsion polymerization, or solution polymerization may be used. Although the degree of polymerization is not particularly limited, it is generally preferred to have a degree of polymerization of 600 to 2.500 degrees.

The rubber-modified resin that is component B used in the present invention is a monomer mixture consisting of a maleimide compound, a vinyl cyanide monomer, and an aromatic vinyl monomer in the presence of a rubber component; acid alkyl ester and/or
or methacrylic acid alkyl ester [hereinafter, (meth)
(collectively referred to as acrylic acid alkyl esters) is added to the monomer mixture by solution or bulk polymerization in such a way that the proportion of maleimide compounds contained in the polymerized monomer mixture before and after phase inversion changes. The proportion is 3 to 11% by weight in the first stage before phase inversion and 12% in the second stage after phase inversion.
It is obtained by carrying out two-step graft polymerization so that the amount becomes 42% by weight.

Examples of the rubber component used here include polybutadiene, styrene-butadiene block polymer, nitrile rubber, maleated rubber, polyisoprene rubber, butadiene-acrylonitrile rubber, and ethylene-propylene-genter polymer. The amount of this rubber component used is 4 parts by weight per 100 parts by weight of the monomer mixture.
It is preferable to adjust the amount to 40 parts by weight, particularly preferably 5 to 35 parts by weight. If it is less than 4 parts by weight, impact resistance will be insufficient, and if it exceeds 40 parts by weight, heat resistance and processability will be reduced.

Among the monomer polymers to be graft-polymerized to this rubber component, examples of maleimide compounds include N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-butylmaleimide, and N-tertiary maleimide. Examples include butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-hydroxyphenylmaleimide, N-lauroylmaleimide, and one or a mixture of two or more of these may be used.

Examples of vinyl cyanide monomers include acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, with acrylonitrile being particularly preferred. In addition, aromatic vinyl monomers include styrene, α
-methylstyrene, 0-chlorostyrene, p-chlorostyrene, vinyltoluene, etc., and one or a mixture of two or more of these may be used.

Furthermore, as the (meth)acrylic acid alkyl ester, those whose alkyl group usually has 1 to 22 carbon atoms are preferable, and specifically, methyl (meth)acrylate, ethyl (meth)acrylate, (meth)acrylate, etc. Butyl acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate,
Lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, (meth)acrylate
Examples include benzyl acrylate, and one of these
Species or mixtures of two or more species may be used.

The composition of these monomer mixtures is 5 to 35% by weight for the maleimide compound, particularly preferably 8 to 30% by weight; if it is less than 5% by weight, the heat resistance will not improve, and if it exceeds 35% by weight. impact resistance and workability decrease. For vinyl cyanide monomers, 3 to 30% by weight, particularly preferably 5 to 25% by weight.
If it is less than 3% by weight, the impact resistance will not improve, and if it exceeds 30% by weight, the heat resistance will decrease. The aromatic vinyl monomer is 45 to 92% by weight, preferably 60 to 92% by weight.
It is 85% by weight, and if it is less than 45% by weight, it becomes brittle.
If it exceeds 92% by weight, no improvement in heat resistance or impact resistance will be observed. Furthermore, in the case of (meth)acrylic acid alkyl ester, it is 0 to 25% by weight, particularly preferably 0 to 20% by weight, and this monomer is added as necessary to improve properties such as heat resistance and processability. used, but 25% by weight
If it exceeds this, the impact resistance will not improve.

The two-step graft polymerization using such a rubber component and a monomer mixture is carried out, for example, as follows. First, a predetermined amount of a solution prepared by dissolving a rubber component in a solvent or an aromatic vinyl monomer and adding a vinyl cyanide monomer or an alkyl (meth)acrylic acid ester to the polymerization system is first added.
Stir to mix well. Next, while purging the polymerization system with nitrogen gas, a first aromatic vinyl monomer solution in which a predetermined amount of a maleimide compound is dissolved is added and polymerized under stirring, usually at 90 to 120°C, and the phase is inverted. Continue polymerization until

From the point of phase inversion, as a second step, a second aromatic vinyl monomer solution in which a predetermined amount of maleimide compound is dissolved is added to continue the polymerization, and the polymerization is allowed to proceed until the target conversion rate is reached. That's fine.

Here, the proportion of maleimide compound contained in the polymerized monomer mixture is 3 to 11% by weight in the first stage before phase inversion.
, particularly preferably from 4 to 10% by weight, and in the second stage after phase inversion from 12 to 42% by weight, particularly preferably from 13 to 40% by weight. If the proportion of the maleimide compound in the first stage is less than 3% by weight or the above proportion in the second stage is less than 12% by weight, sufficient heat resistance cannot be obtained, and the above proportion in the first stage If it exceeds 11% by weight or if the proportion in the second stage exceeds 42% by weight, impact resistance and processability will deteriorate.

In addition, in the above-mentioned graft polymerization method, regarding the phase inversion of the polymerization system, the viscosity of the polymerization system changes rapidly at the time of phase inversion.
In other words, it can be easily determined by a significant decrease in viscosity or an increase in turbidity (becomes markedly cloudy).

In addition, in the above graft polymerization method, various known initiators such as henzoyl peroxide, lauroyl peroxide, dicumyl peroxide, and azobisisobutyronitrile are used as necessary to promote the polymerization reaction. In addition, various additives such as polymerization regulators may be added to the polymerization system. In addition, the polymerization method may be either bulk polymerization method or solution polymerization method. In the solution polymerization method, an appropriate solvent such as benzene, toluene, xylene, chlorobenzene, bromobenzene, or a mixture thereof is used.
There is no particular difference from the bulk polymerization method other than the use of this solvent. Furthermore, the method of supplying the maleimide compound into the polymerization system in the first and second stages is not limited to the above-mentioned means, and various other methods can be used.

By such a graft polymerization method, the polymerization solution that has reached the target conversion rate is then dried under reduced pressure using a thin film distillation machine, a Flasher-1 extruder, etc., to form pellets or the like, which is component B of the present invention. It is considered to be a rubber-modified resin in granular form. The molecular weight of the resin component excluding the rubber component in this resin is not particularly limited, but generally the weight average molecular weight by GPC is about 50,000 to 300,000.
It is preferable that it is in the range of .

The vinyl chloride resin composition of the present invention is prepared by blending the above-described rubber-modified resin as component B with the vinyl chloride polymer as component A and uniformly mixing. Here, the blending ratio of the above two components is 5 to 150 parts by weight of component B to 100 parts by weight of component A, particularly preferably 7 parts by weight.
The amount is preferably 110 parts by weight. If component B is less than 5 parts by weight, heat resistance and impact resistance will decrease, and if it exceeds 150 parts by weight, processability will deteriorate, so both are not preferred.

The method for uniformly mixing components A and B is not particularly limited, and both components may be mixed in advance using a Henschel mixer, ribbon blender, etc., and then melt-mixed using a Banbury, extruder, roll, etc. Alternatively, both components may be melt-kneaded while being quantitatively supplied to a continuous kneader.

The vinyl chloride resin composition of the present invention contains small amounts of heat stabilizers, plasticizers, antioxidants, ultraviolet absorbers, fillers, lubricants,
Foaming agents, flame retardants, processing aids, pigments, etc. can be added as appropriate.

〔Effect of the invention〕

The vinyl chloride resin composition of the present invention has good processability and exhibits excellent physical properties such as heat resistance and impact resistance, so it is widely used in various fields such as building materials, automobile parts, and home appliances. can do.

〔Example〕

Next, the present invention will be specifically explained using reference examples, examples, and comparative examples. Hereinafter, parts and % mean parts by weight and % by weight, respectively.

Reference Example 1 Polybutadiene [trade name Diene 35 manufactured by Asahi Kasei Kogyo 01]
200 parts of AS) and 1.500 parts of styrene were placed in a polymerization pot and stirred to completely dissolve the rubber.

After dissolving, 145 parts of acrylonitrile was added and stirred to mix well.

Next, gas was replaced by blowing nitrogen into the polymerization reactor, and when the temperature was raised to 108°C, 24.3 parts of N-phenylmaleimide and 0.251 parts of benzoyl peroxide were dissolved in 686 parts of styrene in advance. The first thing I kept
The dropwise solution of the step was added quantitatively over a period of 149 minutes.

At this time, the viscosity of the system suddenly decreased and the system became cloudy, indicating a phase inversion.

At this time, a small amount of sample was taken out from the polymerization vessel and unreacted N-phenylmaleimide was detected by gas chromatography, but no unreacted N-phenylmaleimide was detected. Furthermore, the solid content at this point was measured and found to be 17.3%.

Subsequently, at the same temperature, a second stage dropping solution in which 241 parts of N-phenylmaleimide and 0.289 parts of benzoyl peroxide were previously dissolved in 656 parts of styrene was quantitatively dropped over 213 minutes. Polymerization continued.

After the dropwise addition was completed, the solution was rapidly cooled to 50° C., a small amount of the sample was taken out, and the amount of unreacted N-phenylmaleimide and acrylonitrile was measured by gas chromatography. Although N-phenylmaleimide was not detected, it was found that acrylonitrile was contained at 0.83% (based on the polymerization solution).

In addition, when the solid content concentration of the polymerization solution was measured, it was found to be 36.8.
%Met.

Finally, the polymerization solution was dried under reduced pressure to obtain a rubber-modified resin.

In addition, when the ratio of the maleimide compound (N-phenylmaleimide) in the monomer mixture polymerized in the first and second stages in the above polymerization method was determined by the following formula, it was 10.0 in the first stage. %, 29.1 in the second stage
%Met.

M, = Amount of maleimide compound dropped in the first stage M2 - Amount of maleimide compound dropped in the second stage Y, = Total amount of the amount charged in the polymerization kettle and the amount of liquid dropped in the first stage A = In the first stage Solid content (%) in the polymerization solution Z = amount of rubber charged in the polymerization pot Regarding the rubber modified resin obtained in this way, its resin composition and the molecular weight of the resin excluding the rubber component measured by the method below. are shown in Table 2 below.

Molecular Weight> Approximately 1 g of the rubber modified resin is accurately weighed, mixed with a mixed solvent of methyl ethyl ketone and methyl alcohol, and left overnight. Thereafter, the supernatant liquid was diluted with tetrahydrofuran by centrifugation, and then the molecular weight (weight average) was measured by GPC.

Reference Example 2 In the same manner as Reference Example 1, polybutadiene (diene 35A
Pour 200 parts of S) and 1,500 parts of styrene into a polymerization pot, stir to dissolve the rubber, add 145 parts of acrylonitrile, mix well, and after purging with nitrogen, raise the temperature to 108°C and reach this temperature. Then, the first and second stages in Reference Example 1
A solution of the combined drops of the above steps, ie, a solution of 265.3 parts of N-phenylmaleimide and 0.540 parts of benzoyl peroxide dissolved in 1,342 parts of styrene, was quantitatively added dropwise over a period of 360 minutes for polymerization.

After the dropwise addition was completed, the mixture was rapidly cooled to 50° C. in the same manner as in Reference Example 1 to stop the polymerization. At this time, a small sample was taken and the amount of unreacted acrylonitrile and N = phenylmaleimide was measured by gas chromatography.
- Phenylmaleimide was not detected, but ffi found that it contained 0.84% acrylonitrile. Moreover, the solid content of the polymerization liquid was 36.7%.

Finally, the polymerization solution was dried under reduced pressure to obtain a rubber-modified resin. The resin composition and the molecular weight measured in the same manner as above are shown in Table 2 below.

Reference Examples 3 to 12 As shown in Table 1, the amount charged in the polymerization kettle, the polymerization temperature, the composition of each dropping liquid in the first stage and the second stage, and the dropping time were changed,
Further, polymerization was carried out in the same manner as in Reference Example 1 except that N-cyclohexylmaleimide was used instead of N-phenylmaleimide. After polymerization, the mixture was rapidly cooled to 50° C. and then dried under reduced pressure to obtain rubber-modified resins of the present invention and comparison. (first stage, which occurs when phase inversion occurs) and at the end of polymerization (second stage)
In step), unreacted N-cyclohexylmaleimide was checked in the same manner as in Reference Example 1, but none was detected.

The solid content at each point in time and the amount of unreacted acrylonitrile contained in the reaction system after polymerization were measured, and the amount of maleimide compound occupied in the polymerized monomer mixture at each point in time was calculated. Table 2 shows the resin composition of the obtained rubber-modified resin and the molecular weight measured in the same manner as above.

Reference Example 13 In the same manner as Reference Example 1, polybutadiene rubber (
300 parts of diene 35AS) and 1,8 parts of α-methylstyrene
After stirring to dissolve the rubber, 140 parts of acrylonitrile was added and mixed well.

Next, after nitrogen substitution, the temperature was raised to 105°C, and at the same time as reaching this temperature, 0.327 parts of benzoyl peroxide and 14.3 parts of N-phenylmaleimide were added in advance.
The first dropping solution, in which 514 parts of styrene had been dissolved in 514 parts of styrene, was quantitatively added dropwise over a period of 141 minutes to effect polymerization. At this time, phase inversion was observed in the reaction system.

At this time, a small amount of sample was taken out and unreacted monomer was rubbed 8 times, but no N-phenylmaleimide was detected. Further, the solid content at this point was examined and found to be 18.8%.

Subsequently, at the same temperature, 0.452 parts of benzoyl peroxide and 100 parts of N-phenylmaleimide were added in advance.
．． A second dropping solution in which 5 parts of styrene had been dissolved in 503 parts of styrene was quantitatively added dropwise over a period of 206 minutes to continue polymerization.

After the dropwise addition was completed, the temperature was rapidly cooled to 50°C and unreacted monomers were examined. No N-phenylmaleimide was detected, but acrylonitrile was found to be 0.74%. The solid content of the polymerization solution was 39.2%.

Finally, the polymerization solution was dried under reduced pressure to obtain a rubber-modified resin.

1st. The amount of the maleimide compound in the polymerized monomer mixture in the second stage, the resin composition of the obtained rubber-modified resin, and the molecular weight measured in the same manner as above are shown in Table 2 below.

Reference Example 14 In the same manner as in Reference Example 1, polybutadiene (diI) was added to the polymerization pot.
After charging 180 parts of 35AS) and 1,600 parts of methylene chloride and stirring to dissolve the rubber, 170 parts of acrylonitrile was further added and mixed well.

Next, after placing it under nitrogen for tA, the temperature was raised to 105°C, and at the same time as this temperature was reached, 0.289 parts of hensyl peroxide and 27.4 parts of N-phenylmaleimide were added in advance.
53° of methyl methacrylate and 2 parts of styrene.
The first dropping solution, which had been dissolved in 31 parts, was quantitatively added dropwise over a period of 139 minutes to effect polymerization.

At this time, a phase inversion was observed in the reaction system, so a small amount of sample was taken out from the polymerization reactor and unreacted particles were examined by gas chromatography, but N-phenylmaleimide and methyl methacrylate were not detected. Further, the solid content at this point was examined and found to be 18.4%.

Subsequently, at the same temperature, 0.359 parts of benzoyl peroxide and 147.2 parts of N-phenylmaleimide were added in advance.
part and 83.4 parts of methyl methacrylate to 6 parts of styrene.
A second dropping solution, which had been dissolved in 38 parts, was added dropwise over a period of 214 minutes to continue polymerization.

After the dropwise addition was completed, the temperature was rapidly cooled to 50° C., and unreacted monomers were measured. N-phenylmaleimide and methyl methacrylate were not detected, but acrylonitrile was detected at 0.
It contained 78%. In addition, the solid content of the polymerization solution is 39.4
%Met.

Finally, the polymerization solution was dried under reduced pressure to obtain a rubber-modified resin.

1st. The amount of the maleimide compound in the polymerized monomer mixture in the second stage, the resin composition of the obtained rubber-modified resin, and the molecular weight measured in the same manner as above are shown in Table 2 below.

In addition, in Tables 1 and 2, AN is acrylonitrile, MMA
is methyl methacrylate and BPO is benzoyl peroxide.

Example 1 Vinyl chloride resin [trade name Sumilit 5X manufactured by Sumitomo Chemical @
-11F, degree of polymerization 1,050), the rubber modified resin obtained in Reference Example 1, and various additives were mixed in a Henschel mixer at the following composition.

Vinyl chloride resin 100 parts Rubber modified resin 30 parts Lead stearate
0.8 parts barium stearate 0
．． 6 parts 3 parts 3 basic lead sulfate 2 parts Next, this mixture was kneaded for 5 minutes with a hot roll heated to a surface temperature of 185°C to form a sheet, which was then kneaded using a flat plate press at 190°C and 100 kg/d. Press molding was carried out under the following conditions for 10 minutes to prepare test pieces made of vinyl chloride resin compositions for each test described below.

Comparative Example 1 A test piece was prepared in the same manner as in Example 1, except that the rubber modified resin obtained in Reference Example 2 was used instead of the rubber modified resin obtained in Reference Example 1.

Examples 2 to 8 The rubber modified resins obtained in Reference Examples 1.3, 4, and 13.14 were used, and the number of parts of this and vinyl chloride resin used was as shown in Table 3. Seven types of test pieces were prepared in the same manner as in Example 1.

Comparative Examples 2 to 10 Same as Example 1, except that the rubber modified resins obtained in Reference Examples 1.5 to 12 were used, and the number of parts of this and vinyl chloride resin used was as shown in Table 3. Nine types of test pieces were prepared.

Comparative Example 11 A test piece was prepared in the same manner as in Example 1, except that no rubber modified resin was used and the number of vinyl chloride resin used was 100 parts.

Using each test piece prepared in Examples 1 to 8 and Comparative Examples 1 to 11 above, the Vicat softening temperature, which is an index of heat resistance, the Izot impact strength, which is an index of impact resistance, and The melt flow rate, which is an index of processability, was measured. The results were as shown in Table 3 below. It should be noted that the higher the value of each of these measured values, the better the heat resistance, impact resistance, and workability.

Vicat softening temperature: JTS K7206, Method A Izot impact strength: JIS K7110, notched As is clear from the results in Table 3 above, the vinyl chloride resin composition according to this specification exhibits good processability. It can also be seen that it has excellent properties in both heat resistance and impact resistance.

Claims (1)

[Claims] (1) In the presence of A) 100 parts by weight of a vinyl chloride polymer, B) 4 to 40 parts by weight of a rubber component, 5 to 5 parts by weight of a maleimide compound
A monomer consisting of 35% by weight, 0 to 25% by weight of alkyl acrylate and/or alkyl methacrylate, 3 to 30% by weight of vinyl cyanide monomer, and 45 to 92% by weight of vinyl aromatic monomer. 100 parts by weight of the mixture is subjected to solution or bulk polymerization, in the first step before phase inversion, the proportion of the maleimide compound in the polymerized monomer mixture is in the range of 3 to 11% by weight, and in the second step after phase inversion. A vinyl chloride resin composition is characterized in that 5 to 150 parts by weight of a rubber-modified resin obtained by two-step graft polymerization is blended so that the proportion is in the range of 12 to 42% by weight.