JPS60130614A - Rubber-modified aromatic monovinyl polymer resin composition - Google Patents

Abstract

PURPOSE:The titled composition having an excellent total quality balance among colorability, impact strength, gloss, and rigidity, prepared by dispersing rubber- like substance particles containing a high-cis-polybutadiene and characterized by an internal structure in a resin phase. CONSTITUTION:The titled composition in which the rubber-like substance comprises a polybutadiene containing at least 50wt% high-cispolybutadiene containing 90mol% or above cis-1,4-bonds; the rubber-like substance is dispersed in the form of particles in a resin phase of an aromatic monovinyl polymer, its average particle diameter is 0.5-1.6mu, and its particle diameter distribution is 1.1-2.0; its particle contains aromatic monovinyl polymer particles in its interior, and at least 80% of the particles have a diameter <=0.3mu; and the index of swelling, in toluene, of the dispersed rubber-like substance containing this aromatic monovinyl polymer in its interior is in the range of 7-12, and which is obtained by dissolving the rubber-like substance in the aromatic monovinyl monomer and polymerizing the mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rubber-modified aromatic monovinyl polymer resin composition having an excellent overall quality balance.

Compared to conventional ABS resins, rubber-modified aromatic monovinyl polymer resins, such as rubber-modified polystyrene, have the disadvantages of inferior gloss on the surface of molded products, low impact strength, and poor texture when colored. Ta. Recently, there has been a growing demand in the market for rubber-modified polystyrene that has properties close to those of ABS resin due to cost reductions and a desire for thinner materials. Traditionally, rubber-modified polystyrene was used as a rubber-like substance.
Polybutadiene, butadiene-styrene copolymer, etc. are bath-dissolved into styrene monomer, and after polymerization is made into dispersed rubber particles while stirring, they are subjected to either bulk polymerization or solution (solvent bulk 9 polymerization method) or suspension polymerization (・The so-called bulk-suspension polymerization method is common.The content of rubbery substances in the product is 3.
~10% by weight was in one copy. If the amount of rubber is further increased, the viscosity in the polymerization apparatus increases, which impedes stirring, and it is difficult to reduce the rubber particle size. Even if the amount of rubber is increased to about 15% by weight, The impact strength is
Even if dyes and pigments are added to the natural-colored resin to tone it, the finished texture is poor, and the gloss and rigidity are significantly reduced.The present inventors have overcome these drawbacks and created an excellent product. As a result of extensive research into a rubber-modified aromatic vinyl polymer resin composition that has a comprehensive quality balance of colorability, impact strength, gloss, and opacity, the present invention was achieved.

That is, the present invention is a rubber-modified aromatic vinyl polymer resin composition characterized by a specific microstructure, particularly rubber-like material particles dispersed in a resin phase and the internal structure of the particles. It is.

In the rubber-modified aromatic monovinyl polymer resin of the present invention, the (,1 rubber-like substance is a polybutadiene containing 50% by weight or more of high-cis polybutadiene containing 90% by mole or more of cis 1,4 bonds, ( The rubbery substance is dispersed in the resin phase of an aromatic monovinyl polymer in the form of particles, and the average particle size of the dispersed particles is in the range of 05 to 1.6 microns, preferably 08 to 13 microns, and the particle size distribution is 20 or less, preferably 1.5 or less, (
C) An aromatic monovinyl polymer is incorporated in the particles of the dispersed rubber-like material in the form of particles, and 80% of the number of particles.
03 microns or less, preferably 90% or more is 02 microns
(dl) The swelling index of the dispersed rubber-like material containing the aromatic monovinyl polymer in toluene is required to be in the range of 7 to 12.

The resin composition of the present invention has good colorability, impact strength, and gloss.

Injection molded products have an excellent quality overall balance of rigidity.

It is expressed in extruded sheets, extruded vacuum-formed products, etc.

Expensive hBs4! It has great value as an economical resin that can replace tBVI, make products thinner, and reduce costs.

As the rubber-like substance used in the present invention, high-cis polybutadiene containing 90 mol% or more of cis-1,4 bonds, or polybutadiene containing 50% by weight or more of cis-1,4 bonds, has good impact resistance, especially 1liJ impact at low temperatures. It is preferable from the viewpoint of excellent properties. Stain-butadiene copolymer rubber (SBR) is generally used as a rubber-like substance, and when this SDR is used, it is often found that it has excellent coloring properties, but it is especially resistant to impact at low temperatures. It is undesirable due to its poor strength.

By using polybutadiene and controlling the microstructure of the resin, the present invention was able to achieve an excellent overall quality balance of colorability, gloss, rigidity, and impact strength. Of course, rubber such as SBR may be used in combination as long as it does not impede the object of the present invention.

The above-mentioned high-cis polybutadiene is produced by a known production method such as using a catalyst containing an organic aluminum compound and a cobalt or nickel compound.

In order to achieve the object of the present invention, the average particle size of the rubbery material dispersed in the resin phase of the aromatic monovinyl polymer is in the range of 05 to 16 microns, preferably 08 to 1.3 microns. , and its particle size distribution must be 20 or less, preferably 1.5 or less. Average particle size is 05
If it is smaller than 16 microns, the impact resistance will be poor, and if it is larger than 16 microns, the gloss and rigidity will deteriorate, which is not preferable.

Furthermore, if the particle size distribution is as wide as 20 or more, the gloss, especially at a distance from the gate of the molded article, will be significantly reduced.

Furthermore, in order to achieve the object of the present invention, 80% or more of the number of particles of the particulate aromatic monovinyl polymer (offlusion) incorporated in the particles of the dispersed rubbery substance is 03.
It is necessary that the fineness is less than microns, preferably 90% or more is less than 0.02μ, which is considerably finer than that of ordinary rubber-modified polystyrene.

By finely controlling offfusion in this way and keeping the rubber particle diameter in the range of 05 to 1.6 microns and the distribution below 20, colorability, gloss, and 111
11 properties are significantly improved. In order to obtain desirable physical properties, it is safe to ensure that the three requirements of rubber particle size, its distribution, and fineness of offfusion are met.

Furthermore, in order to achieve the object of the present invention, the crosslinking state of the dispersed rubbery material containing the aromatic monovinyl polymer is also important, and the swelling index in toluene should be in the range of 7 to 12. is necessary. If the swelling index is less than 7, the impact strength will drop significantly, and if it is thicker than 12, the impact strength will drop, as well as the rigidity and gloss, which is not preferable.

The method for producing the resin of the present invention employs a bulk polymerization method or a bulk suspension polymerization method in which monomers are polymerized in the presence of a rubbery substance. As a method for producing a rubber-modified aromatic vinyl polymer resin having a special microstructure specified in the present invention, in a polymerization solution containing a rubbery substance and an aromatic monovinyl monomer, a rubbery substance and an aromatic monovinyl monomer are mixed together. It is also possible to employ a method in which the proportion of the rubber-like material in relation to the monovinyl monomer is increased compared to that generally used heretofore.

That is, 10 to 25 parts by weight of the rubbery material and 90 to 75 parts by weight of the aromatic monovinyl monomer, preferably 12 to 25 parts by weight of the rubbery material.
A polymerization solution is prepared in a ratio of 20 parts by weight to 88 to 80 parts by weight of an aromatic monovinyl monomer, and polymerization is carried out. If the proportion of the rubbery substance in the polymerization solution is as low as has conventionally been the case, it is not possible to obtain the dispersed rubber particle size 1 particle size distribution and fine occlusion defined in the present invention. It is not clear why it is possible to obtain a more preferable microstructure by increasing the proportion of the rubbery substance, but the state at which the rubbery substance undergoes a phase transformation during polymerization and is dispersed in the form of particles is not clear. will be different. Furthermore, if the proportion of rubbery substances is too high, the viscosity of the solution becomes too high, making it difficult to handle.

After the polymerization reaction is completed, a step of removing unreacted monomers and a step of heat treatment are performed. By appropriately selecting the conditions (temperature, time, etc.) for the subsequent heat treatment step, the swelling index of the dispersed rubbery material in toluene can be controlled. The rubber-modified resins thus produced can also be diluted with polystyrene for end use.

The rubber-like substance used in the present invention is polybutadiene containing 50% by weight or more of polybutadiene containing 90% by mole or more of diss-1.4 bonds. It is preferable that the 5% by weight styrene solution has a very low viscosity of 20 to 60 cps.

The aromatic monovinyl monomer in the present invention includes styrene and 0-methylstyrene7. p-methylsteref, m-)
Nuclear alkyl-substituted styrenes such as f-styrene, 2,4-dimethylstyrene, etherstyrene, p-tert-methyl, and X-styrene;
O-chlorostyrene.

m-chlorostyrene, p-chlorostyrene, p-bromostyrene, 2-methyl-1,4-chlorostyrene, 2.
Nuclear halogenated styrenes such as 4-dichlorostyrene and 2.4-cyphlomostyrene, butylnaphthalene,
It can be used alone or as a mixture of two or more.

A solvent can be present during the polymerization reaction, and aromatic hydrocarbons such as toluene, xylene,
Ethylbenzene can be used alone or in a mixture of two or more. Furthermore, other solvents such as aliphatic hydrocarbons and dialkyl ketone 7 may be used in combination with the aromatic hydrocarbons to the extent that they do not impair the dissolution of the rubbery substance and the polymerization product from the aromatic monovinyl monomer. can.

The aromatic monovinyl monomer solution of the rubbery substance can be polymerized in the temperature range of 100 to 180°C in the absence of a polymerization initiator. An initiator is used.

Organic peroxides that generate radicals can be used as polymerization initiators in the present invention. Polymerization is carried out at a temperature of 50 to 150 DEG C., preferably 90 DEG to 135 DEG C., with stirring, either at a constant temperature or at a gradually increasing temperature until the rubber-like substance is granulated.

The organic peroxide used in the present invention is 1,1-bis(1
-butylperoxy)cyclohexane.

1.1-bis(t-butylperoxy) 3,3.5-
Peroxyketals such as trimethylcyclohexane,
Di-t-butyl peroxide, 2,5-dimethy/I/
Dialkyl peroxides such as -2,5-di(t-butylperoxynohexane), sialic silver oxides such as benzoyl peroxide, m-)luoyl peroxide, and peroxydicarbonate such as dylmyristyl peroxydicarbonate. Carbohydrates, peroxy esters such as t-butylbaroxyinzolopyl carbonate a
, ketone peroxides such as nclohexanone peroxide, p-menotahydroperoxide.

There are hydroperoxides such as.

Chain transfer agents such as mercaptans, α-methylstyrene linear dimer, terpinolene, antioxidants such as hindered phenols, hindered bisphenols, hindered bisphenols, etc., such as 2.6-di-t-butyl-4-methyl Phenol, stearyl-β
-(3,5-di-t-butyl-4-hydroxyphenyl fugropionate can be added.

Furthermore, additives such as dyes and pigments, lubricants, fillers, mold release agents, plasticizers, and anti-seizure agents may be added to the resin of the present invention as required.

It is also possible to use a resin composition obtained by mixing or melt-kneading the resin of the present invention with beads or pelleted polystyrene. It is also possible to use a resin composition mixed or kneaded with other polymers than polystyrene.

The rubber-modified aromatic vinyl polymer resin having both the microstructure specified in the present invention, especially the rubber particle size and fineness of the off-fluidity of the present invention, has a good overall quality balance in terms of physical properties such as gloss, rigidity and impact strength of 1J. It has excellent coloring properties. Good coloring properties are of great industrial significance, as the cost of dyes and pigments used for coloring can be significantly reduced.

The resin of the present invention can be used as molded products in fields such as light electrical equipment and miscellaneous goods. Particularly favorable results can be obtained in molded products that require vivid colors.

Examples are shown below. The data shown in the examples were measured based on the following method.

Izot impact strength: According to JrSK7110.

Flexural modulus: Based on ASTM D790.

Swelling index in toluene: Add 201 toluene to the resin of 1 and shake vigorously for 1 hour to dissolve or swell.

Next, the gel is sedimented using a centrifuge, the supernatant liquid is separated by decantation, and the sedimented gel is weighed.

The toluene-swollen gel thus obtained was heated at 160°C.
It is dried for 45 minutes at normal pressure and then for 15 minutes under reduced pressure of 3 to 5 μHg, cooled in a desiccator, and then weighed. The swelling index is expressed as the quotient obtained by dividing the weight of the toluene-swollen gel by the weight of the dry gel.

Gloss: The glossiness (incidence angle of 60°) of the gate portion and end gate portion of the ASTM D638 dumbbell test piece was measured.

Colorability: 100 parts by weight of resin and black thread dye pigment total 0.019
A fixed amount of 3 parts by weight was added to make a molded piece (vertical 89-1 horizontal 5QlIlIn thickness 2.5 mm) as a black colored product.
Create. As a control sample, dyes and pigments were added to polystyrene containing 9% by weight of polybutadiene rubber (black molded pieces were made, and the color and texture were compared and ranked. Naturally colored high-impact polystyrene with 1-2
Black-colored molded pieces prepared by adding dyes and pigments worth 5 yen, 20 yen, and 1 to 5 yen are designated as oil-resistant samples A, B, and C, respectively.

Evaluation is made by adding a certain amount of dye and pigment, and from ranks 0 to 5, higher ranks indicate excellent coloring properties.

Particle size of built-in aromatic monovinyl polymer: Beads or pellets are stained with osminium tetroxide, ultrathin sections are prepared, and electron micrographs are taken. The particle size of the aromatic monovinyl polymer contained within the particles of the dispersed rubbery material enlarged in the photograph is measured to 0.005 μm. In the case of an elliptical shape, the particle diameter is determined by the average value of the major axis aa1'b and the minor axis, ie, □.

Particle size and particle size distribution of rubbery substances in resin: Coulter Counter (Coulter Counter ■TA-II type)
Using an electrolyte mixed with dimethylformamide (dimethylformamide) and ammonium tonaocyanate, place 2 to 4 resin pellets in dimethylformamide and leave for about 2 to 5 minutes. The median diameter of 50% is defined as the average particle diameter.

The particle size distribution is calculated by calculating the number average particle size and weight average particle size from a chart (relationship between particle size and weight fraction) obtained by measuring with a Coulter counter.

Examples 1-2. Comparative Examples 1 to 3 The viscosity of the 5% by weight styrene solution was 35 cps, and 1
．． 4 cis bond 96 mol%, 1.4) lance bond 2 mol%
, 1.2 To 100 parts of a solution of high 7 sulfur cyclodiene having a microstructure of 2 mol % of vinyl bonds dissolved in styrene monomer (see Table 1 for the ratio of polyptadiene and styrene monomer), 4 parts of ethyl pen, 5 parts of ethyl pen, mineral oil 1
parts, 1.1-bis(t-butylperoxy) 3,3.
5-) Add 005 parts of remethylcyclohexane to prepare a polymerization raw material solution.

The raw material liquid was continuously fed into a continuous three-stage polymerization machine to perform polymerization. Each polymerizer has a capacity of 1.2-e and is equipped with stirring blades. The polymerization temperature was varied between 105 and 145°C, and the polymerization was carried out until the solid content reached approximately 80% at the final polymerization machine.Then, the unreacted styrene monomer and Ethylbenzene is removed, the strands are pulled from the die, cooled with water, and then cut into pellets. After measuring the content of rubbery substances in the pellets, if necessary, use homopolystyrene (Styron ■683) at 30IOI.
A rubber-modified polystyrene resin with a rubber content of 9% was obtained by diluting it using a φ single-screw extruder.The resin with a rubber content of 9% was injection molded to create a test piece, and the physical properties shown in Table 1 were obtained. was measured. The results are shown in Table-1.

As is clear from Table 1, when the rubbery substance/styrene monomer ratio is low as in Comparative Example 1, fine obfusations cannot be obtained. In addition, as shown in Comparative Example 2, if the rubber particle diameter becomes thick due to a change in the stirring rotation speed of the polymerization tank, desirable physical properties cannot be obtained. However, if the swelling index deviates from the range of the present invention, the impact strength in particular decreases, which is undesirable.

(after that)

Claims (1)

[Scope of Claims] (1) An aromatic monovinyl polymer resin obtained by bath-dissolving and mixing a rubbery substance with an aromatic monovinyl monomer and polymerizing the mixture, wherein the rubbery substance has a cis 1.4 It is a polybutadiene containing 50% by weight or more of high cis polybutadiene containing 90% by mole or more of bonds, and (b) the rubbery substance is dispersed in the form of particles in the resin phase of the aromatic monovinyl polymer. The average particle size of the particles is 0.5 to 1.6 microns and the particle size distribution is 11-λ0, and (c) the aromatic monovinyl polymer is contained in the particles of the dispersed rubbery substance in the form of particles. (d) The dispersion rubber-like material containing the aromatic monovinyl 1 aggregate has a swelling index of 7 to 7 in toluene.
Rubber-modified aromatic monovinyl polymer resin composition 2, wherein the rubber-modified aromatic monovinyl polymer resin composition 2 has a composition similar to that of 12% in the resin phase of the aromatic monovinyl polymer. The average particle diameter of the dispersed rubbery substance is 08 to 1.3.
Rubber-modified aromatic monovinyl polymer resin composition 3, characterized in that the particle size distribution is 15 microns or less, and the rubber-modified aromatic monovinyl 1 coalescence of Claim 1 or J-2i Rubber-modified aromatic monovinyl polymer resin composition 4 cis 1, characterized in that in the resin, 90% or more of the aromatic monovinyl polymer particles incorporated in the particles of the dispersed rubber-like substance are 0.2 microns or less. In a bath in which polybutadiene containing 50% by weight or more of high-7 polybutadiene containing 90% by mole or more of 4-bonds is dissolved in an aromatic monovinyl monomer, 10 to 25 parts by weight of the polybutadiene and 50% by weight or more of the aromatic monovinyl monomer are used. Claim 1, characterized in that the polymerization is carried out in the absence or presence of an inert solvent, in which the solution is present in a proportion of 90 to 75 parts by weight. Method 5 for producing a rubber-modified aromatic monovinyl polymer resin composition according to , 1'2 or 3. In the production method according to claims 1-4, the viscosity of a 5% by weight styrene solution of polybutadiene used A method for producing a rubber-modified aromatic monovinyl polymer resin composition, characterized in that