JPH02167324A - Maleimide-based block copolymer and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject copolymer excellent in heat resistance, flow molding properties, compatibility with other resins, etc., and suitable for a molding material, an additive to a resin, etc., by copolymerization of a vinyl monomer with a maleimide polymer having a specified viscosity-average molecular weight. CONSTITUTION:(A) A block unit expressed by formula l (R1 and R2 are H, halogen, etc.; R3 is 1-18C alkyl, etc.) and having 2000-500000 viscosity-average molecular weight is prepared by adding a polymeric peroxide to a maleimide such as N-methyl maleimide and reacting the resultant mixture. (B) Another block unit represented by formula II (R4 is H or methyl; R5 is H, chlorine, phenyl, etc.) and having 2000-500000 viscosity-average molecular weight is prepared by adding a vinyl monomer (e.g. ethylene) thereto and carrying out polymerization, thus carrying out copolymerization with the above-mentioned component (A) and obtaining the objective copolymer.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a maleimide-based block copolymer and a method for producing the same. More specifically, the present invention relates to a maleimide block copolymer and a method for producing the same. A maleimide block copolymer useful as a molding material obtained by polymerizing the same as an additive for improving heat resistance when added to other resins or as a compatibilizer in polymer blends, and its '7R manufacturing method. .

<Prior Art> Homopolymers of maleimide compounds and copolymers with vinyl monomers are known as resins with high heat resistance. Furthermore, it has been proposed to improve heat resistance by adding a random copolymer of a maleimide compound and methyl (meth)acrylate to vinyl chloride resin (Japanese Patent Laid-Open No. 61-16
Publication No. 2543).

On the other hand, using polymeric peroxide as an initiator,
It is also known to polymerize vinyl monomers in two stages to obtain block copolymers. For example,
No. 845 discloses a block copolymer having a methyl (meth)acrylate polymer and polystyrene as block units, and JP-A-59-202261 discloses a block copolymer having a wider range of vinyl polymers as block units. Block copolymers are disclosed.

By the way, homocopolymers of maleimide compounds have excellent heat resistance, but have the drawbacks of extremely poor flow processability and poor compatibility with other resins. Therefore, no resin has hitherto been obtained that satisfies both heat resistance and flow processability. Furthermore, the above-mentioned known literature regarding block copolymers does not describe maleimide-based block copolymers.

<Problems to be Solved by the Invention> The purpose of the present invention is to provide an additive that simultaneously combines mechanical properties such as flow processability and heat resistance, and improves the heat resistance of other resins as a molding material. An object of the present invention is to provide a maleimide block copolymer useful as a compatibilizer in polymer blends, and a method for producing the same.

<Means for Solving the Problems> According to the present invention, - enlargement (1) (wherein R□ and R2 each represent a hydrogen atom, a halogen atom, or a methyl group, and R1 has a carbon number of 1 to 18 (represents a straight chain or branched alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a substituted aryl group) having a viscosity average molecular weight of 2,000 to 50,000.
Block unit A in the range of 0 and dispersion CI (-CH, -CR4Rs-) --' (II) (in the formula,
R4 represents a hydrogen atom or a methyl group, and R1 represents a hydrogen atom, a chlorine atom, a phenyl group, an alkyl-substituted phenyl group, an acetyl group, a nitrile group. However, RG is an alkyl group having 1 to 18 carbon atoms. ) has a viscosity average molecular weight of 2000.
An AB type block copolymer consisting essentially of block units B in the range of ~50oooo is provided.

According to the present invention, the general formula (III) R1 (wherein R and R2 each represent a hydrogen atom, a halogen atom, or a methyl group, and R1 is a linear or branched alkyl group having 1 to 18 carbon atoms, a carbon It represents a cycloalkyl group having 3 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a substituted aryl group.

) A maleimide polymer having a peroxy group in the molecule obtained by polymerizing the maleimide compound represented by () in the presence of a polymeric peroxide.

General formula (IV) CH,=CRIR,...(IV) (In the formula, R4 represents a hydrogen atom or a methyl group, and R7 represents a hydrogen atom, a chlorine atom, a phenyl group, an alkyl-substituted phenyl group, an acetyl group, a nitrile group, or C-0RG, where Ro is an alkyl group having 1 to 18 carbon atoms.

This will be explained in more detail below.

The maleimide block copolymer of the present invention comprises a block unit A consisting of a maleimide compound constituent unit (hereinafter abbreviated as MIC) and a specific vinyl compound constituent unit (hereinafter abbreviated as VC) in a homopolymer or random copolymer. It is an A-B type block copolymer consisting essentially of block units B.

In the present invention, the block unit A is represented by the following general formula (1)
In the formula, R1 and R2 each represent a hydrogen atom, a halogen atom, or a methyl group, and R3 is a straight-chain or branched alkyl group having 1 to 18 carbon atoms, or a cyclo group having 3 to 12 carbon atoms. It represents an alkyl group, an aryl group having 6 to 18 carbon atoms, or a substituted aryl group. At this time, if R1 is a branched alkyl group, an aryl group, or a substituted aryl group having 19 or more carbon atoms, or a cycloalkyl group having 13 or more carbon atoms, it cannot be used because production becomes difficult. Monomers forming the MIC represented by the general formula (1) include 1, for example, N-methylmaleimide,
N-ethylmaleimide, N-n-propylmaleimide,
N-1-propylmaleimide, N-t-butylmaleimide, N-dodecylmaleimide, N-octadecylmaleimide, N-2-ethylhexylmaleimide, N-phenylmaleimide, N-2-methylphenylmaleimide, N-
It is preferably selected from one or more of the group consisting of -3-isopropylphenylmaleimide, N-benzylmaleimide, and the like.

In the present invention, the block unit B is represented by the following general formula (II
) as a constituent unit, CH,=CR4R5 where R4 represents a hydrogen atom or a methyl group, and R8 represents a hydrogen atom, a chlorine atom, a phenyl group, an alkyl-substituted phenyl group, an acetyl group , a nitrile group or -C-OR.

represents struggle. However, RI is an alkyl group having up to ↓8 carbon atoms, and in this case, when Rs has 19 or more carbon atoms, it is difficult to manufacture and is therefore not preferred. 1γIffj3 General formula (■
Examples of monomers forming VC-1 represented by ) ethyl acrylate, n-butyl (meth)acrylate, etc.
It is preferably selected from one or more of the group consisting of meth)acrylic acid esters, acrylonitrile, methacrylonitrile, vinyl chloride, and the like.

The polymeric peroxide used in producing the maleimide block copolymer of the present invention is
It can be produced by the method described in Japanese Patent No. 666, and preferred examples include compounds represented by the following general formula.

(In the formula, R7 represents an alkylene group having 2 to 10 carbon atoms, R, is an alkylene group having 2 to 10 carbon atoms, -CH2CH
,OC:H2CH,-or-CH2CH,OCH,CH
, OCH2CR2-.

Also, R3 is -C(CH3), CH, CH, C(CH3), --c(
cH,), -0-c(cH3)2-, R□. represents an alkylene group or phenylene group having 2 to 1 carbon atoms. ).

The amount of the polymeric peroxide used is preferably in the range of 0.2 to 20% by weight based on the total amount of monomers constituting the block copolymer, 98.8 to 80% by weight.

If it is less than 0.2% by weight, it is not preferable because one polymerization becomes extremely slow and problems such as polymerization not being completed occur. 2
If it exceeds 0% by weight, there is a risk that the monopolymerization reaction will run out of control, so it is not preferable.

In order to produce the maleimide-based block copolymer of the present invention, the MIC monomer is polymerized in the presence of the polymeric peroxide, that is, using the polymeric peroxide as a polymerization initiator, and the maleimide-based block copolymer having a polymeric peroxy residue in one molecule is produced. Combine, ie, prepare block unit A. Next, by polymerizing the block unit A and the VC-1 monomer constituting the block unit B, a maleimide-based block copolymer consisting of the block units AB can be produced. The polymerization method at this time can be any of the suspension polymerization method, solution polymerization method, solvent suspension polymerization method, bulk polymerization method, etc., but from the viewpoint of blocking efficiency, it is preferable to use a solvent with large chain transfer. do not have. Even if the polymerization operation is carried out continuously, or after producing block unit A v4, it is taken out from the reaction system and block unit B is
Polymerization may also be carried out. Further, the order of polymerization of the block units is not particularly limited, and any polymerization order may be a block copolymer consisting of block units AB. It is desirable that the temperature during the polymerization is usually in the range of 30 to 120°C, preferably in the range of 40 to 90°C. Further, when polymerizing block units A and B, the polymerization time is preferably in the range of 0.5 to 10 hours for each, and 1 to 20 hours in total.

The completion time for producing block unit A is determined by the charging ratio of maleimide and the polymerization rate.

It is usually desirable that the amount of residual monomer is 0.5% by weight or less. If the amount of residual monomer exceeds 0.5% by weight, a removal process such as washing will be necessary when polymerizing block lli position B, which will complicate the process, which is not preferable.

The viscosity average molecular weight of the block unit A thus obtained is in the range of 2,000 to 500,000, and the viscosity average molecular weight of the block unit B is also in the range of 2,000 to 50,000.
It is in the range of 0. These molecular weights can be determined by known methods such as limiting viscosity or gel permeation chromatography. If the molecular weight of each block unit is less than 2,000, the molecular weight is too small, so the heat resistance of the maleimide polymer of block unit A cannot be sufficiently expressed, and the mechanical properties of the vinyl monomer polymer of block unit B are poor. This is not preferable as it will result in insufficient performance.

Further, when the molecular weight exceeds 500,000, the molecular weight is too high, resulting in extremely poor flow processability and poor compatibility with other resins, which is not preferred.

The molecular weight of the entire maleimide block copolymer of the present invention can be determined by a method such as a light scattering photometer, an intrinsic viscosity method, or a gel permeation chromatography method. or,
The proportion of maleimide in the block copolymer can be determined by measuring the total nitrogen content using single-element analysis or Kelpool method, and the proportion of vinyl monomer can be determined by infrared absorption spectroscopy or nuclear magnetic resonance analysis. . Further, the proportion of the block copolymer in the copolymer, that is, the blocking efficiency, can be determined by fractionating or oil-separating the non-block polymer and measuring its weight.

<Effects of the Invention> The maleimide block copolymer of the present invention has the high heat resistance of a maleimide homopolymer, the flow processability, compatibility with other resins, mechanical strength, etc. of a vinyl polymer. Because of this, it is a well-balanced resin as a heat-resistant molding material, and can be used as an additive to other resins to improve their heat resistance.

It is also useful as a compatibilizer in polymer blends of different polarities.

<Examples> Next, the present invention will be explained in more detail using reference examples and examples. All parts in these examples refer to parts by weight.

A fourth flask equipped with a thermometer and a stirrer was charged with 183 parts of adipic acid dichloride and 75 parts of triethylene glycol, and then placed under a stream of nitrogen gas.

When stirred at 20°C for 60 minutes, triethylene glycol bis(adipoyl chloride) 2 became a viscous colorless liquid.
Got 10 copies.

Next, a fourth flask equipped with a thermometer, a stirrer, and a dropping funnel was charged with 50% hydrogen peroxide and 210 parts of a 20% potassium hydroxide aqueous solution to prepare a potassium peroxide aqueous solution. Next, while stirring vigorously and keeping the reaction temperature at 5 to 7°C, 176 parts of triethylene glycol bis(adipoyl chloride) prepared previously was added dropwise over 20 minutes. then 1
When stirring was continued for an hour, a white solid was produced. The white solid produced was filtered off, washed twice with IQ cold water, and then dried in vacuo. The weight was 145 parts.

This was measured using a vapor pressure equilibrium method molecular weight measuring device (rV newly manufactured by Hitachi).
When measured with "Po-115 type"), it was 2620 (n = 6.5). The amount of active oxygen measured by iodometry was 2.21%, and the purity was 99.6%.

Next, as a result of measuring the infrared absorption spectrum, 1725a
The absorption of the carbonyl group of the ester group at ++-1 is 178
Absorption of the carbonyl group of the diacyl group was observed at 0.1805an-'', and absorption of the peroxy group was observed at 875-1.

A fourth flask equipped with a thermometer, a stirrer, and a Dimroth condenser was charged with 300 parts of a 0.5% by weight aqueous solution of polyvinyl alcohol (saponification degree 88%). Next, 80 parts of cyclohexylmaleimide and 10 parts of cyclohexylmaleimide (n = 6.5) prepared in Reference Example were dispersed and charged in 20 parts of methyl ethyl ketone. Next, polymerization was carried out at 65°C for 4 hours with stirring while purging the inside of the reactor with nitrogen gas, and then cooled to room temperature and a part of the produced polymer was taken out and purified and analyzed using the following method. Ta. That is, the polymer was washed with water, dissolved in chloroform, and poured into a large amount of methanol to precipitate the polymer. This was filtered and dried under vacuum to obtain a white powder. The intrinsic viscosity of the obtained white powder was measured at 30° C. in toluene. The intrinsic viscosity [η] was 0.486, and the viscosity average molecular weight was 148,000. The amount of active oxygen in the polymer determined by iodometry was 0.25%, and the content of peroxy groups introduced into the molecules of the polymer was 6.4%. Then, when an infrared absorption spectrum was measured, the absorption of the carbonyl group of the polymeric peroxide was found to be 1695a at 1805.17800-1.
Absorption of the carbonyl group of the maleimide ring was observed at a-'.

A chart showing the infrared absorption spectrum is shown in FIG.

From the above points, it was found that this polymer was a cyclohexylmaleimide polymer having peroxy bonds in the molecule.

Next, in the reaction vessel containing the maleimide polymer,
While stirring, 80 parts of styrene monomer was added at room temperature, and the mixture was stirred and dispersed for 1 hour. Then increase the temperature.

Polymerization was carried out at 80°C for 10 hours. Living! The cut polymer was dissolved in chloroform and poured into a large amount of methanol to precipitate the polymer. This was filtered and dried under vacuum to obtain 148 parts of a white polymer.

The intrinsic viscosity of the obtained white polymer was measured in toluene at 30°C, and the intrinsic viscosity [η) was 1.02, and the viscosity average molecular weight was 4.15000.

Also, as a result of measuring the infrared absorption spectrum, -1 of 1695
Absorption of the carbonyl group of the maleimide group was observed, but no absorption of the carbonyl group of the polymeric peroxide was observed. As a result of hydrogen nuclear magnetic resonance analysis, absorption by the phenyl ring of styrene was observed. Charts representing this infrared absorption spectrum and nuclear magnetic resonance spectrum are shown in FIGS. 2 and 3, respectively.

Next, unblocked polystyrene was extracted using a Soxhlet extractor using cyclohexane as a solvent, and the blocking efficiency was determined from its weight.

As a result, the blocking efficiency was 74%.

From the above points, it was found that this polymer is a block copolymer containing cyclohexylmaleimide polymer and polystyrene as block units. Types of maleimide and vinyl monomers in block units, proportions of each block unit,
A maleimide block copolymer was produced in the same manner as in Example 1, except that the type and amount of polymeric peroxide used, the degree of polymerization, and the time were changed. The conditions and results are shown in Table 1.

Using the block copolymer prepared in Example 1 in which polycyclohexylmaleimide and polystyrene are used as block units, the thermal properties and mechanical properties were measured by the methods shown below.

A test piece was prepared by press-molding the block copolymer powder for 10 minutes in a hot press at 230° C. and a pressure of 120 kg/cJ, then forming a sheet and punching the sheet.

As for thermal properties, Vicat softening point (JISK-720
6), and also to melt flow rate 1 (JISK-7
210) uses a simple melt indexer and a load of 10
Measured in kg/-. Furthermore, tensile strength at break and elongation were also measured at the same time. The results are shown in Table 2.

A test piece was prepared in the same manner as in Example 12, except that a copolymer obtained by copolymerizing 50 parts of cyclohexylmaleimide and 50 parts of styrene was used. and mechanical properties were measured. The results are shown in Table 2.

table Continued

[Brief explanation of the drawing]

Figure 1 is a chart showing the infrared absorption spectrum of the cyclohexylmaleimide polymer having peroxy bonds in the molecule produced in Example 1, and Figure 2 is the infrared absorption spectrum of the maleimide block copolymer produced in Example 1. This is a chart showing the spectrum, and FIG. 3 is also a chart showing the nuclear magnetic resonance spectrum.

Claims (1)

[Claims] 1) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (I) (In the formula, R_1 and R_2 each represent a hydrogen atom, a halogen atom, or a methyl group, and R_3 represents a straight chain or branched alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, an aryl group or substituted aryl group having 6 to 18 carbon atoms, and has a viscosity average molecular weight of 2000 to 50.
Block unit A in the range of 0000 and general formula (II) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼... (II) (In the formula, R_4 represents a hydrogen atom or a methyl group, and R_
5 represents a hydrogen atom, a chlorine atom, a phenyl group, an alkyl-substituted phenyl group, an acetyl group, a nitrile group, or ▲a mathematical formula, a chemical formula, a table, etc.▼. However, R_6 is an alkyl group having 1 to 18 carbon atoms. ) and a block unit B having a viscosity average molecular weight in the range of 2,000 to 500,000, which is a single or random copolymer having B as a constituent unit. 2) General formula (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (III) (In the formula, R_1 and R_2 each represent a hydrogen atom, a halogen atom, or a methyl group, and R_3 is a straight carbon number of 1 to 18. (representing a chain or branched alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a substituted aryl group) in the presence of a polymeric peroxide. A maleimide polymer having a peroxy group in the molecule, and a maleimide polymer having the general formula (IV) CH_2=CR_4R_5...(IV) (wherein R_4 represents a hydrogen atom or a methyl group, and R_7
represents a hydrogen atom, a chlorine atom, a phenyl group, an alkyl-substituted phenyl group, an acetyl group, a nitrile group, or ▲a mathematical formula, a chemical formula, a table, etc.▼. However, R_6 is an alkyl group having 1 to 18 carbon atoms. ) A method for producing a maleimide block copolymer, which comprises polymerizing a monomer represented by: