JPS63196643A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To make it possible to form a thermoplastic resin composition excellent in appearance, heat resistance, weather resistance, impact resistance and moldability, by mixing a specified copolymer with a vinyl chloride polymer. CONSTITUTION:A thermoplastic resin composition comprising the following copolymer (I) and a vinyl chloride polymer (II) and excelling in heat resistance, weather resistance, impact resistance and moldability, (I): a copolymer obtained form 5-30wt.% maleimide compound (A) of formula I (wherein R is H, a 1-4C alkyl or cyclohexyl), 25-45wt.% methyl methacrylate, 40-60wt.% styrene and 0-30wt.% other polymerizable monomer copolymerizable therewith (B) (provided that the total of these percentages is 100wt.%). The mixing ratio in this resin composition is preferably such that copolymer (I) is 5-50wt.% and vinyl chloride polymer (II) is 50-95wt.%.

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention is applicable to heat resistance, weather resistance, impact resistance, moldability, and construction materials such as ridge materials and sizing, electrical equipment parts, automobile parts, pipes, etc. The present invention relates to a thermoplastic resin composition useful for manufacturing various molded products such as bosses and disks.

Specifically, the present invention relates to a thermoplastic resin composition comprising a vinyl chloride polymer and a copolymer essentially containing a maleimide compound, methyl methacrylate, and styrene in specific proportions.

(Prior art) Vinyl chloride resin has excellent physical and chemical properties and is used in a wide range of areas. However, in recent years, when applications have become more diverse, their use is currently restricted depending on the application.

To improve heat resistance, there is a so-called post-chlorinated vinyl chloride resin that is made by further chlorinating vinyl chloride resin with chlorine, but although it has improved heat resistance compared to conventional vinyl chloride resin, it has poor moldability. is extremely bad, and its range of applications is severely limited.

To improve molding processability, there has been a conventional method of adding acrylic resin containing methyl methacrylate as a main component as a processing aid (Japanese Patent Publication No. 52-1746, Japanese Patent Publication No. 52-1746).
No. 49020) and methods that make extensive use of plasticizers have been adopted.

If these acrylic processing aids are added, the molding processability will be improved, but the heat resistance will be reduced. In particular, in the case of post-chlorinated vinyl chloride resin, a large amount of processing aid is required, and in some cases, it may be necessary to use a blend with conventional vinyl chloride resin to achieve the heat resistance originally possessed by the resin. Therefore, it is forced to have low heat resistance. To improve the weather resistance of vinyl chloride resins, a method of blending them with acrylic resins has been adopted, and to improve their impact resistance, a method of blending them with graft polymers containing soft rubber components has been adopted. There are, but
In either case, heat resistance decreases.

As described above, although individual properties have been improved by conventional methods, thermoplastic resin compositions with good heat resistance, weather resistance, impact resistance, and moldability have not yet been produced.

(Problems to be Solved by the Invention) In view of these points, the present inventors have conducted extensive research and found that by using a specific 9 copolymer, heat resistance, weather resistance, impact resistance, and It has been discovered that a thermoplastic resin composition with improved moldability can be obtained, and the present invention has been completed.

(Actions and means for solving the problems) The present invention has the following features: General formula 1-(-C=C-H I3 o=c　　c=.

(In the formula, R is hydrogen, an alkyl group having 1 to 4 carbon atoms, or a cyclohexyl group.) 5 to 30% by weight of maleimide compound (A), 25 to 30% by weight of methyl methacrylate
45% by weight, 40 to 60fflffi% of styrene, and other polymerizable ω-forms (B
)0 to 30% by weight (however, the total of the monohedrons is 1% by weight) Appearance and heat resistance consisting of copolymer (I) obtained from 1% by weight and vinyl chloride polymer (If) ,Weatherability,
The present invention provides a thermoplastic resin composition having excellent water resistance, impact resistance, and moldability.

Since the copolymer (I) in the present invention itself has excellent colorless transparency, heat resistance, weather resistance, etc., it has excellent heat resistance, water resistance, etc. without impairing the appearance etc. of the vinyl chloride polymer (n). sex,
Molding processability etc. can be improved.

The copolymer (I) essentially contains the maleimide compound (A), methyl methacrylate, and styrene, and if necessary, other polymerizable monomers (8) are used in combination.

The maleimide compound (A) not only imparts heat resistance and solvent resistance to the resin composition, but also has the expected effect of suppressing resin deterioration by capturing free chlorine in the resin composition and reducing electrical resistance. It also exhibits effects that were previously absent.

Methyl methacrylate has weather resistance, water resistance, impact resistance,
A component for improving optical properties.

In plastic products, improved water resistance is particularly preferable because it greatly contributes to dimensional stability.

Styrene improves processability when molding the thermoplastic resin composition of the present invention, and also serves as a maleimide compound (A).
As a result of increasing the copolymerizability of the unreacted maleimide compound (A>ffi), it contributes to improving productivity and makes the effect of improving heat resistance more pronounced.

Therefore, the resin composition of the present invention consisting of the copolymer (I) and the vinyl chloride polymer (n) has a synergistic effect of each component of the copolymer (I), so that the resin composition of the present invention is superior to the conventional vinyl chloride polymer The excellent physical properties, chemical properties, and flame retardancy of the resin composition are maintained (heat resistance, weather resistance, water resistance,
The result is a thermoplastic resin composition with improved impact resistance, excellent one-method stability, and low free mt.

The maleimide compound (A) used in the copolymer (I) is represented by the above general formula, such as maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isobutylmaleimide. , N-butylmaleimide, N-isobutylmaleimide, N-tert-butylmaleimide, N-cyclohexylmaleimide, etc., and one or more of these can be used. Compound (A) is present in copolymer (I) in an amount of 5 to 30 ffi1%, preferably 10
Use at a ratio of ~20%. If the amount of the maleimide compound (A) used is less than 51%, sufficient heat resistance cannot be imparted to the resulting resin composition;
If the amount is more than % by weight, the molding processability of the resulting resin composition and the miscibility with the vinyl chloride polymer (II) will deteriorate, so both are not preferred.

Methyl methacrylate is used in a proportion of 25 to 45% by weight, preferably 30 to 40% by weight, in coΦ polymer (I). If the amount of methyl methacrylate used is less than 25% by weight, the weather resistance and molding processability of the resulting resin composition will decrease, and if the amount is more than 45% by weight, sufficient heat resistance will be imparted to the resulting resin composition. Both are undesirable because it makes it impossible to do so.

Styrene is used in a proportion of 40 to 60% by weight, preferably 45 to 55% by weight, in copolymer (I). If the amount of styrene used is less than 40% by weight, the copolymerizability of the maleimide compound (A) will decrease, and as a result, the effect of improving heat resistance will not be sufficiently expressed, and if the amount is more than 60% by weight, the resin composition obtained Both are unfavorable because the mechanical properties of the material deteriorate.

The copolymer <I) is obtained by using the maleimide compound (A) represented by the above general formula, methyl methacrylate, and styrene, respectively, and is colorless and transparent only under limited conditions in the present invention. A copolymer (I) with excellent heat resistance, weather resistance, etc. can be obtained, and therefore has excellent heat resistance, weather resistance, impact resistance, and moldability without impairing the appearance and other characteristics of the vinyl chloride polymer (II). The thermoplastic resin composition of the present invention which is excellent in both properties can be obtained. For example, if another N-substituted maleimide is used in place of the maleimide compound (A), or if one of the three components is used at an ω that deviates from the matrix defined in the present invention, the above characteristics will no longer be achieved. A thermoplastic resin composition that satisfies all aspects cannot be obtained.

In obtaining copolymer (I), if necessary, copolymer (
7 reimide compound (I) in a proportion not exceeding 30% by weight in
A), methyl methacrylate, and other polymerizable 1ffi forms (B) that can be copolymerized with styrene can be used together.

Examples of other copolymerizable monomers (B) include unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, or half-esterified products thereof; methyl acrylate, ethyl ( meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, tertiary-butyl(meth)acrylate, amyl(meth)acrylate, octyl(meth)acrylate, 2-ethylhexyl(meth)acrylate,
Cycloalkyl groups such as lauryl (meth)acrylate, Schiff 0 hexyl (meth)acrylate, benzyl (meth)acrylate, acrylic acid esters having an alkyl group with a carbon number of 1 to 12, including a benzyl group, or an alkyl group with a carbon number of 2 methacrylic acid esters having 12;
Vinyl aromatics other than styrene such as α-methylstyrene, paramethylstyrene, isopropenylstyrene, and vinyltoene; Unsaturated nitriles such as (meth)acrylonitrile; Olefins such as ethylene and propylene; Dienes such as butadiene and isoprene : Vinyl esters such as vinyl acetate; Vinyl halides such as vinyl chloride and vinyl fluoride; Ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, divinylbenzene, etc. Examples include polyunsaturated compounds, and one or more selected from these groups can be used.

Polymerizable polymer (B) may be added to copolymer (I) if necessary.
It is used in an amount of ω% or less, preferably 15% or less. In the present invention, the polymerizable monomer (B
) as unsaturated carboxylic acids in copolymer (I) 1 to 3
It is preferable to use it in a proportion of 0% by weight, preferably in a proportion of 1 to 15% by weight, since the effect of improving heat resistance is further exhibited. If the amount of the polymerizable monomer (B) exceeds 30% by weight, a resin composition with excellent heat resistance, impact resistance, and moldability cannot be obtained.

The vinyl chloride polymer (n) used in the present invention is a vinyl chloride copolymer containing 80% by weight or more of a vinyl chloride component, or a chlorinated vinyl chloride copolymer obtained by further adding chlorine to the copolymer, Used alone or in combination.

The method for producing the thermoplastic resin composition of the present invention includes:
Although not particularly limited, conventionally known methods such as a method of simply mixing polymers mechanically, suspension polymerization, emulsion polymerization, bulk polymerization, or an appropriate combination of these methods can be employed. For example, after mixing copolymer <I) obtained by suspension polymerization, bulk polymerization, etc. and polymer (II), 150
A method of preparing a thermoplastic resin composition by melting, cross-wiring, and extrusion at a temperature of ~300°C: Presence of copolymer <I) in the monomer mixture used to produce the polymer (If) A method of bulk polymerization, suspension polymerization or emulsion polymerization in an aqueous medium containing a suspension stabilizer; the polymer (II) is present in the monomer mixture constituting the copolymer (I), Method of bulk polymerization, suspension polymerization or emulsion polymerization: Copolymer (I)!
The monomer mixture used to produce the polymer (II) is emulsion polymerized, and then the monomer used to produce the polymer (II) is added to the obtained emulsion copolymer, polymerized, and uniformly dispersed. Examples include a method in which a powdery resin composition is obtained by producing an emulsion with high properties, followed by coagulation, washing with water, and drying.

The polymerization reaction employed to produce the thermoplastic resin composition of the present invention is carried out at temperatures ranging from 0°C or lower to 100°C or higher under autogenous pressure or under pressure and in an inert gas atmosphere. It will be held in

The polymerization initiator used during the polymerization is a commonly used free radical polymerization initiator, such as oil-soluble or water-soluble peroxides such as benzoyl peroxide, potassium persulfate, ammonium persulfate, hydrogen peroxide, etc. Azo compounds such as azohisisobutyronitrile are suitable. Also, 1 cum sodium bisulfite, ascorbic acid, lil! It is also possible to use a reducing agent such as ferrous acid in combination to effectively advance the polymerization.

Suspension stabilizers used during suspension polymerization include commonly used suspension stabilizers such as calcium carbonate, barium carbonate, magnesium carbonate, polyvinyl alcohol,
An alkali metal salt of a copolymer of methacrylic acid and methacrylic ester may be used.

Emulsifiers used during emulsion polymerization include commonly used emulsifiers, such as anionic emulsifiers such as potassium oleate, sodium dodecylbenzenesulfonate, and sodium lauryl sulfate: polyoxyethylene nonylphenol ether, polyoxyethylene sorbitan ester Nonionic emulsifiers such as nilauryltrimethylammonium chloride and cationic emulsifiers may be used as appropriate.

The organic solvents used during solution polymerization are commonly used organic solvents, such as toluene, xylene, methyl isobutyl ketone, butyl cellosolve, dimethyl formamide, 2-methyl biOlidone, and Tsurpets +100 (manufactured by Fuburn Petrochemical Co., Ltd.). ) may be used as appropriate.

The outline of the production of the copolymer (I) constituting the resin composition of the present invention will be explained below using a suspension polymerization method as an example.

Suspension stabilizers such as polyvinyl alcohol are dissolved in an aqueous solution at room temperature or under heating, and maleimide compound (A), methyl methacrylate, styrene and, if necessary, other polymerizable monomers copolymerizable with these are added. A homogeneous mixture obtained by adding and dissolving a polymerization initiator (e.g., benzoyl peroxide) to a monomer mixture of polymer (B) is added to the mixture under stirring and inert gas (e.g., nitrogen gas) to form a suspension. Thereafter, the temperature is raised to a predetermined reaction temperature (usually 60 to 100° C.) to initiate polymerization, and the predetermined temperature range is maintained for a certain period of time to complete the polymerization. After completion of the polymerization, the reaction product is subjected to the following steps: cooling, filtration, washing with water, and drying to obtain the desired copolymer (I).

Most of the maleimide compound (A) constituting the copolymer (I) is solid at room temperature, so in some cases it may not be completely soluble in the organic solvent used or other 1$1ffi compounds such as methyl methacrylate and styrene at room temperature. There is. In such a case, taking the above suspension polymerization as an example, a monomer mixture containing no polymerization initiator is added to an aqueous suspension stabilizer solution with stirring, and then other monomers of the maleimide compound (A) are added. After heating to a temperature higher than the solubility in the body and uniformly suspending it, a polymerization initiator is added and polymerized to form the desired copolymer (
A method such as obtaining I) may be adopted.

The molecular weight of the copolymer (I) is not particularly limited, but if it is too high, the moldability of the resin composition may deteriorate,
In addition, if it is too low, there will be disadvantages such as poor weather resistance, heat resistance, mechanical properties, etc., so it is usually 5,000 to 2
,000.000° Preferably 10.000~i,oo
A range of o, ooo is preferable. To adjust the molecular weight, commonly used chain transfer agents such as butyl mercaptan, tertiary dodecyl mercaptan, mercaptoethanol, etc. may be used.

The thermoplastic resin composition of the present invention can be obtained from the copolymer (I) and the vinyl chloride polymer (I) by the various methods described above.
Engineering) 5 to 50% by weight, vinyl chloride polymer (II) 50
The proportion is ~95% by weight.

If the proportion of copolymer (I) used is outside the above range and has a low ω, the resulting resin composition may have insufficient heat resistance and moldability, and the use of copolymer (I) Even if the ratio exceeds the above range, the effect commensurate with the amount used may not be sufficiently obtained and it may become uneconomical, and the versatility of the resin composition may be impaired, so care must be taken.

When the polymer (II) is a post-chlorinated vinyl chloride polymer, the resin composition of the present invention has excellent heat resistance and moldability, but does not have drawbacks such as decreased heat resistance like conventional compositions. There is no visible difference, and the original characteristics can be fully demonstrated.

In addition, conventionally known additives can be used in combination with the thermoplastic resin composition of the present invention within a range that does not impair the object of the present invention.

If the resin composition requires higher impact resistance, for example, an acrylic ester, a methacrylic ester, or cyanide may be added in the presence of 15 to 80 parts by weight of polybutadiene or a butadiene copolymer containing 50 parts by weight or more of butadiene. A graft copolymer obtained by copolymerizing 85 to 20 parts by weight of a 1ffi mixture consisting of one or more monomers selected from vinyl compounds and an aromatic vinyl compound, preferably a maleimide compound, is used in combination. or methacrylate in the presence of 15 to 80 parts by weight of a copolymer consisting of 100 to 80% by weight of an acrylic acid alkyl ester, 0 to 20% by weight of a monomer copolymerizable therewith, and an appropriate amount of a crosslinkable 1ω substance. acid ester, acrylic acid alkyl ester, aromatic vinyl compound,
A graft copolymer obtained by copolymerizing 20 to 85 parts of a 1lffi mixture of a vinyl cyanide compound and, if necessary, a maleimide compound, may be used in combination. These graft copolymers are produced by known methods, generally emulsion polymerization.

Further, a copolymer containing methacrylic acid ester as a main component may be used as a processing aid, and in some cases as a plasticizer for the vinyl chloride polymer (n).

Examples of other additives include phthalic acid, trimellitic acid,
Plasticizers such as octyl ester of pyromellitic acid Stabilizers such as nidibutyltin dimaleate, lead stearate, zinc stearate Mold release agents such as nistearic acid and calcium stearate; Fillers such as calcium carbonate and titanium oxide;
Examples include bleaching agents and ultraviolet absorbers.

(Effects of the invention) The thermoplastic resin composition of the present invention has excellent appearance, heat resistance, weather resistance,
Because it has excellent water resistance, impact resistance, and moldability, it is used in general-purpose engineering plastics such as building materials, automobile parts, and electric appliance parts, as well as in special fields such as diskettes.

Next, the present invention will be explained in more detail with reference to Examples, but it goes without saying that the present invention is not limited to these Examples. In addition, parts in the examples represent heavy products, and % represents mass production %.

Reference Example 1 550 parts of deionized water and 0.28 parts of polyvinyl alcohol (Gohsenol GH-20, manufactured by Nippon Gosei Co., Ltd.) were charged into a 1P stainless steel four-loaf flask equipped with a stirrer.
After heating to 80°C under a nitrogen gas atmosphere to completely dissolve the polyvinyl alcohol, the mixture was cooled to 50°C.

Weigh out 48 parts of cyclohexylmaleimide, 77 parts of methyl methacrylate, and 115 parts of styrene into a separate container, and
After heating to 0.degree. C. to dissolve cyclohexylmaleimide, 9.6 parts of benzoyl peroxide was added and dissolved to obtain a uniform single matrix solution.

Four of the obtained single-body solutions were added to a Lough flask and kept in a suspended state under stirring at 400 rpm for 10 minutes under a nitrogen gas atmosphere, and then the internal temperature was raised to 80°C. Polymerization was initiated and then maintained at this temperature for 7 hours to complete the polymerization. The resulting aqueous suspension was filtered through a 100-mesh filter cloth, thoroughly washed with deionized water, and then dried in a hot air circulation dryer at 90°C to a diameter of 0.51 FI! About 220 parts of R granular copolymer (1) was obtained.

Reference Examples 2 to 5 and Comparative Reference Examples 1 to 4 Same as Reference Example 1 except that 240 parts of a monomer mixture having the composition shown in Table 1 was used instead of the monomer composition in Reference Example 1. Repeat this operation to obtain copolymers (2) to (5).
and comparative copolymers (1) to (4) were obtained.

Examples 1 to 3 Copolymer (1) obtained in Reference Example 1 and vinyl chloride resin (
Sumirit 5X-11F, manufactured by Sumitomo Chemical Co., Ltd., polymerization degree 1
050), resin compositions <1) to <3) having the formulations shown in Table 2 were prepared.

The obtained resin compositions (1) to (3) were each kneaded for 5 minutes using a heated roll with a diameter of 8 inches heated to a surface temperature of 190°C to obtain a sheet-shaped resin composition, which was then kneaded using a flat plate press. A test piece was prepared by press molding at 190° C. for 10 minutes under a pressure of 100 to 9/d. The appearance of the obtained test piece was good, and the results of measuring the softening temperature, Izot 1iff strength, and accelerated weathering resistance using the test piece were shown in the second table.
As shown in the table, it was found that the resin composition of the present invention showed good results. In addition, in each Example, the evaluation results of roll suitability during hot roll kneading of the resin composition are also shown in Table 2, and the results were good without any problems.

In addition, the method for measuring the softness temperature is according to JIS-6745, the Izod l-m impact strength is according to ASTHD-256, and the accelerated weathering resistance is determined by observing the appearance after 1000 hours of irradiation with a sunshine-type ezaometer. Good, Δ:
Slightly poor, ×: poor, roll suitability was determined by observing the heat 0-roll cross-wire condition, ○: good, Δ: slightly poor, ×:
I rated it bad.

Comparative Example 1 A comparative composition (1) was prepared in the same manner as in Example 1 except that the copolymer (1) in Example 1 was not used, and then
A test piece was prepared and evaluated in the same way. The second result is
Shown in the table. Comparative composition (1) showed inferior results compared to resin compositions (1) to (3) obtained in Examples 1 to 3.

Note) M-101A (Dibutyltin dimaleate stabilizer manufactured by Tokyo Fine Chemical @J) E-101 (Dibutyltin dilaurate stabilizer manufactured by Tokyo Fine Chemical ■) Kalen A-88 (Higher alcohol lubricant manufactured by Tokyo Fine Chemical ■) Example 4 -7 and Comparative Examples 2-5 Copolymers (2)-(5) obtained in Reference Examples 2-5 and comparative copolymers (1)-(4) obtained in Comparative Reference Examples 1-4
) was used in place of the copolymer (1) in Example 1, but the resin compositions (4) to (7) had the same composition as in Example 1.
After preparing Comparative Compositions (2) to (5), test pieces were prepared and evaluated in the same manner. The results are shown in Table 3.

Claims (1)

[Claims] 1. A maleimide compound (A) represented by the general formula ▲ Numerical formula, chemical formula, table, etc. )5 to 30% by weight,
Methyl methacrylate 25-45% by weight, styrene 40%
~60% by weight and 0 to 30% by weight of other polymerizable monomers (B) copolymerizable with these monomers (however, the total of the monomers is 100% by weight). A thermoplastic resin composition comprising a polyvinyl chloride copolymer (I) and a vinyl chloride polymer (II), which has excellent appearance, heat resistance, weather resistance, impact resistance, and moldability. 2. The thermoplastic resin composition according to claim 1, wherein an unsaturated carboxylic acid is used as the other polymerizable monomer (B) in an amount of 1 to 30% by weight in the copolymer (I).