JPH0649745B2 - Method for producing resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a method for producing a resin composition having excellent transparency and weather resistance, and having significantly improved impact resistance and mechanical properties.

Specifically, a bifunctional peroxide having two kinds of peroxy bonds having different decomposition temperatures in one molecule is used. First, polymerization is carried out using the peroxy bond, which decomposes at low temperature in the bifunctional peroxide, as a catalyst, and then As a catalyst, the peroxy bond on the side that decomposes at high temperature in the bifunctional peroxide is raised.
The present invention relates to a method for producing a resin composition by carrying out second-stage polymerization.

The resin composition obtained by the method of the present invention is a copolymer (A) obtained by polymerizing the monomer mixture (A), and the monomer mixture.
A copolymer (B) obtained by polymerizing (B), and a block copolymer (C) comprising three components (A) and (B), which is a polymer alloy comprising three components: The presence of (C) compatibilizes the copolymer (A) and the copolymer (B),
It is intended to provide a resin composition in which mechanical properties such as impact resistance are significantly improved without impairing transparency and weather resistance.

b. Conventional technology The most effective means for improving the impact resistance of a resin is to introduce a rubber component into the resin phase. As a method, a rubber component is blended with a resin component, or a resin component graft-polymerized with a rubber component is blended with a resin component.
An excellent impact resistant resin represented by a resin or the like is known.

c. Problems to be solved by the invention However, in these impact resistant resins, the transparency is remarkably impaired, and conventional blended syrups have transparency due to impact polymerization by graft polymerization. For this reason, in addition to the refractive index of the rubber to be blended, the rubber particle size becomes a major point, and it has been difficult to obtain a resin that satisfies both transparency and impact resistance.

d. Means for Solving Problems The present invention uses a bifunctional peroxide having two peroxy bonds having different decomposition temperatures in one molecule as a catalyst,
The first-stage polymerization is carried out using the peroxy moiety of the bifunctional peroxide that decomposes at low temperature as the catalyst, and the second-stage polymerization is the peroxy moiety of the bifunctional peroxide that decomposes at high temperature. The present invention provides a method for producing a resin composition having excellent transparency, weather resistance, and impact resistance, which is characterized by being used as a catalyst.

That is, the present invention, the following monomer mixture (A) 2-40 wt%
In producing a polymer consisting of 60 to 98% by weight of the following monomer mixture (B), a bifunctional peroxide having two kinds of peroxy bonds having different decomposition temperatures in one molecule is used. Using the peroxy moiety of the bifunctional peroxide that decomposes at low temperature as a catalyst, one of the monomers (A) or (B) is added to carry out the first-stage polymerization, and then the temperature is raised. It is characterized in that the peroxy moiety of the bifunctional peroxide that decomposes at high temperature is used as a catalyst to add the monomers not used in the first stage of (A) and (B) and polymerize. The method for producing a resin composition, wherein the monomer mixture (A) has a rubbery α, β-unsaturated carboxylic acid alkyl ester copolymer 40 to 98% by weight, and an aromatic vinyl compound 2 to 60
% By weight, and 0 to 30 other monomers copolymerizable therewith
Monomers, which consist of weight% and whose copolymer is rubbery.

Monomer mixture (B) at least one selected from α, β-unsaturated carboxylic acid alkyl ester and aromatic vinyl compound 60 to 10
0% by weight and other monomers copolymerizable with these 0-40
Monomer consisting of wt%.

Is provided.

The major point in the present invention is to obtain a block polymer composed of a rubber component and a resin component in order to improve the compatibility between the rubber component and the resin component by two-stage continuous polymerization,
The final point is to obtain a resin composition containing a rubber component, a resin component and a block polymer. Therefore, the present invention is characterized by using a bifunctional peroxide having two peroxy bonds having different decomposition temperatures in one molecule, and using a specific monomer in combination.

The present invention will be described in detail below.

Generally, polymer blends composed of heterogeneous polymers generally have poor compatibility, and it is difficult to obtain a satisfactory molded product by causing phase separation during molding. Therefore, as a means of increasing the compatibility between polymers of different components, the technology of producing a block copolymer consisting of each component and adding it to the blend as a compatibilizer has been attracting attention and is effective. It has been known. However, in the conventional technique, a plurality of component polymers and a block copolymer to be blended are separately polymerized and then blended to form a polymer alloy, which is a laborious and non-productive method. Therefore, although it is known that the technique for modifying a polymer blend by adding a block copolymer has a great effect, few examples have been actually applied.

The block-containing resin composition obtained by using the bifunctional peroxide of the present invention is a resin composition obtained by continuous steps, and is industrially advantageous in terms of process, time, cost and the like. In addition, the resin composition is excellent in quality in that it does not contain impurities and that a solution in which the component polymer and the block are uniformly mixed can be obtained.

The bifunctional peroxide used in the present invention is a peroxide having two kinds of peroxy bonds having different decomposition temperatures in one molecule, and specific examples thereof include ditertiary-butyl-peroxytrimethyl adipate and bis. (T-butylperoxy)-
α-n-butyl suberate, bis (t-amyl peroxy) α-n-butyl suberate, bis (t-hexyl peroxy) α-n-butyl suberate, bis (1,1,3,3-
And tetramethylbutylperoxy) α-n-butyl suberate, dicumyl peroxy α-n-butyl suberate and the like.

10 of the two peroxy bonds of these bifunctional peroxides
The time half-life temperature of all compounds was around 70 ° C for the low temperature decomposable peroxy bond side and for the high temperature decomposable peroxy bond side.
Values around 100 ° C. However, dicumylperoxy α-n
-Butyl suberate has a 10-hour half-life temperature of 65 ° C for low-temperature decomposable peroxy bonds and a relatively low temperature of 87 ° C for high-temperature decomposable peroxy bonds.

The amount of these difunctional peroxides used is usually 0.5 to 7 parts by weight, preferably 1 to 6 parts by weight, and more preferably 1.5 to 5 parts by weight, based on 100 parts by weight of the monomers polymerized in the first stage. Partial use is desirable.

The polymerization temperature is preferably about 10 hours half-life temperature of peroxy bond.

Further, during the polymerization reaction using the low-temperature decomposable peroxy bond as a catalyst, even if a part of the polymerization using the high-temperature decomposable peroxy bond as a catalyst is carried out, it may be within the range not hindering the object of the present invention.

The polymerization of the present invention is a method of polymerizing the monomer mixture (A) and then the monomer mixture, or (B) and then
It may be a method of polymerizing (A). Compared with the latter method, the former method is preferable because it provides a good balance of physical properties such as impact strength.

The copolymer (A) obtained by polymerizing the monomer mixture (A),
It is a copolymer mainly used as a rubber-like component of the composition of the present invention. The glass transition point of the copolymer of the component (A) has a great influence on the mechanical properties of the composition of the present invention, and when it is higher than 10 ° C, the elongation at break is small and the impact resistance is low. Also, since it is weak against bending, it is desirable to polymerize with a monomer composition having a glass transition point of preferably 10 ° C. or lower, more preferably 5 ° C. or lower, and particularly preferably 0 ° C. or lower.

As the composition of the monomer (A) which gives a copolymer satisfying the above conditions, an α, β-unsaturated carboxylic acid alkyl ester can be used, and an alkyl group having 2 or more carbon atoms is more preferable. Is preferably 4 to 20, n-butyl acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, Cetyl (meth) acrylate, tridecyl (meth) acrylate, isodecyl (meth) acrylate and the like are used alone or as a mixture.

When the amount of the α, β-unsaturated carboxylic acid alkyl ester used is less than 40% by weight, it is difficult to keep the glass transition point at 10 ° C or lower, and when it exceeds 98% by weight, the monomer mixture (B) is used. The difference in the refractive index from the copolymer obtained by polymerization from the above is large, which adversely affects the transparency of the resin composition. Therefore, it is desirable to use these α, β-unsaturated carboxylic acid alkyl esters in the component (A) in an amount of usually 40 to 98% by weight, preferably 50 to 95% by weight, more preferably 60 to 90% by weight.

As the aromatic vinyl compound, styrene, α-methylstyrene, p-methylstyrene, bromostyrene, etc. are used.

The amount of these aromatic vinyl compounds used is the glass transition point,
And considering the refractive index of the copolymer obtained by polymerizing from the monomer mixture (B), it is necessary to determine,
It is desirable that the component (A) is used in an amount of usually 2 to 60% by weight, preferably 5 to 50% by weight, and more preferably 10 to 40% by weight.

Other monomers copolymerizable with these are used for the purpose of lowering the glass transition point, controlling the refractive index and improving other physical properties, such as budadiene, substituted butadiene, isoprene, acrylonitrile, methacrylonitrile, and copolymerization. Monoethylenically unsaturated monomers such as siaphethyl acrylate, acrylamide, methacrylamide,
Hydroxy lower alkyl acrylate, hydroxy lower alkyl methacrylate, acrylic acid, methacrylic acid and the like are used.

The amount of these monomers used is usually 0 to 30% by weight in the component (A), and it is desirable to select and use a monomer capable of improving the desired physical properties within this range.

Next, the monomer mixture (B) contains at least 60% by weight of an α, β-unsaturated carboxylic acid alkyl ester and an aromatic vinyl compound, and another copolymerizable with these. It is a monomer mixture consisting of 0 to 40% by weight of a monomer, and mainly provides a copolymer (B) which serves as a matrix component of the obtained resin composition. The copolymer (B) has a glass transition point of preferably 60 ° C or higher, more preferably 70 ° C or higher, and particularly preferably 80 ° C or higher. Therefore, it is preferable to select a monomer mixture that gives a resinous polymer having excellent transparency. Α, β in the monomer mixture (B) described in the claims
-As the unsaturated carboxylic acid alkyl ester, alkyl having 1 to 9 carbon atoms is preferable, and methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, cyclohexyl (meth) are preferred. Acrylate, allyl (meth) acrylate and the like are preferable,
Methyl (meth) acrylate, ethyl (meth) acrylate, cyclohexyl (meth) acrylate and the like are particularly preferable monomers, and they are used alone or as a mixture.

The amount of the α, β-unsaturated carboxylic acid alkyl ester used is usually 0 to 100% by weight, preferably 30%, in the component (B).
It is desirable to use about 100 to 100% by weight, more preferably 40 to 95% by weight, and particularly preferably about 50 to 95% by weight.
Since the α, β-unsaturated carboxylic acid alkyl ester has a large effect on the optical properties of the resin composition, it is preferable that the amount used is as large as possible.

Next, as the aromatic vinyl compound, styrene, α-methylstyrene, p-methylstyrene, bromstyrene or the like is used. These aromatic vinyl compounds are copolymerized for the purpose of improving the moldability of the resin composition and the like, but if used in a large amount, birefringence or the like will occur and optical characteristics will be deteriorated, so caution is required. It is also used for the purpose of matching the refractive index with the copolymer (A) obtained by polymerizing the monomer mixture (A).

The amount of the aromatic vinyl compound used is usually 0 to 100 in the component (B).
% By weight, preferably 0-70% by weight, more preferably 5
It is desirable to use -60% by weight, particularly preferably 5-50% by weight.

Other monomers that can be copolymerized with these include acrylonitrile, methacrylonitrile, cyanoethyl acrylate, acrylamide, methacrylamide, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, acrylic acid, methacrylic acid and other copolymerizable monoethylenic Unsaturated monomers, and N-phenylmaleimide,
N-substituted maleimides such as N-cyclohexylmaleimide, N-o-chlorophenylmaleimide, Nn-butylmaleimide and N-octylmaleimide are used. These monomers have a refractive index adjustment with the copolymer (A),
Alternatively, it is used for the purpose of improving the heat resistance of the resin composition and the like, and it is a desirable method to use it in the range of 0 to 40% by weight in the component (B).

Next, the mixing ratio of the monomer mixture (A) and the monomer mixture (B) is a copolymer (A) obtained by polymerizing the monomer mixture (A).
Contributes significantly to the impact resistance of the obtained resin composition, and the larger the amount used, the higher the impact resistance. However, if the amount is too large, the moldability of the resin composition may be extremely reduced. Further, when the amount of the copolymer (A) is small, impact resistance and the like cannot be sufficiently improved. Therefore, the mixing ratio of the monomer mixture (A) and the monomer mixture (B) is usually (A) 2 to 4
0 wt%, (B) is 98-60 wt%, preferably (A) 5-35 wt%, (B) 95-65 wt%, more preferably
(A) is 7 to 30% by weight, and (B) is 93 to 70% by weight.

The transparency characteristic of the resin composition of the present invention includes from transparency such as transparent glass to a state in which the resin composition has transparency. The degree of transparency of these is determined by the selection of the type of monomer and the ratio of its use.

In order to obtain a transparent resin composition, the difference between the refractive index of the polymer of the component (A) and the refractive index of the polymer of the component (B) is preferably 0.02 or less at n ²⁵ _D , more preferably Is
It is 0.01 or less, particularly preferably 0.005 or less.

Most of the resin compositions are used after being colored with a coloring agent. In coloring, the more transparent or transparent the resin composition is, the more transparent the resin composition is,
Vivid and deep coloring is possible. In the market, most of them are desired to have vivid and deep coloring,
Therefore, it is necessary that the resin composition has a high degree of transparency.

Other additives of the resin composition of the present invention, such as plasticizers, stabilizers, ultraviolet absorbers, flame retardants, colorants, mold release agents and glass fibers, fibrous reinforcing agents such as carbon fibers, further glass beads, carbonic acid. Fillers such as calcium and talc may be added.

As the plasticizer, polybutene, low molecular weight polyethylene, mineral oil, epoxidized soybean oil, polyethylene glycol and fatty acid esters are particularly effective. As the stabilizer, phosphite esters, hindered phenols, alkanolamines, acid amides, metal salts of dithiocarbamic acid, inorganic sulfides and metal oxides can be used alone or in combination. . As a flame retardant,
Aromatic phosphates, red phosphorus, aromatic halogen compounds, antimony trioxide, etc. are particularly effective.

In addition, the resin composition of the present invention further comprises other known polymers such as polybutadiene, butadiene-styrene copolymer, acrylic rubber, ethylene-, depending on the required performance.
Propylene copolymer, EPDM, styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer and hydrogenated product, styrene-butadiene-
Styrene radial teleblock copolymer and hydrogenated product, polypropylene, butadiene-acrylonitrile copolymer, polyvinyl chloride, polycarbonate, PET, PB
T, polyacetal, polyamide, polyamide elastomer, epoxy resin, polyvinylidene fluoride, polysulfone, ethylene-vinyl acetate copolymer, polyisoprene, natural rubber, chlorinated butyl rubber, chlorinated polyethylene, PPE resin, PPS resin, polyether ether ketone Etc. may be appropriately blended and used.

e. Examples Next, the present invention will be described in more detail with reference to production examples and examples, but these are merely examples and do not limit the content of the present invention.

In the following examples, parts and% indicate parts by weight and% by weight, respectively.

Example 1 A typical polymerization method of the present invention will be described with reference to Example 1.

14 parts of n-butyl acrylate, 6 parts of styrene, and 6 parts of toluene are added to an autoclave equipped with a stirrer, a condenser, a thermometer, and a monomer introduction port, and they are sufficiently stirred. Thereafter, 0.5 part of bis (t-butylperoxy) -α-n-butyl suberate was added as a catalyst, and the temperature was started with stirring.
The polymerization temperature is maintained at 75 ° C and the polymerization is continued for 7 hours. When the yield at the end of the polymerization does not reach 95% or more, the polymerization is further continued. When the predetermined yield (95% or more) was reached, as the second stage monomer, 72 parts of methyl (meth) acrylate, 8 parts of styrene, 50 parts of toluene, t-dodecyl mercaptan
Add a mixture of 0.3 parts and stir for about 1 hour to make a homogeneous solution. Thereafter, the temperature was raised and polymerization was carried out at 110 ° C. for 3 hours and at 130 ° C. for 2 hours. The polymerization yield was almost 100%.
The Tg of the second-stage polymerization component was 103 ° C. After cooling, the polymer was removed from the autoclave, the solvent and the like were removed by a steam strip, then crushed by a crusher, dried, and pelletized by using an extruder. Various physical properties were measured using a molded product obtained by injection molding the resin composition thus obtained.

The test results are shown in Table-3.

Examples 2 to 6 [Production of Various Resin Compositions] Various resin compositions were obtained by changing the monomer composition, the catalyst and the like according to the polymerization method shown in Example 1.

The results are shown in Table-1. The test results are shown in Table 3.

Comparative Examples 1 to 5 Polymerization was carried out in the same manner as in Example 1 except that the monomer composition, the polymerization catalyst and the polymerization temperature shown in Table 2 were used. The results of evaluating the physical properties of the obtained resin composition are shown in Table-3.

Comparative Examples 1 and 5 are examples in which a catalyst outside the scope of the present invention was used, and the molded products of the obtained resin composition were severely delaminated and could not be evaluated.

Comparative Example 2 is an example in which the amount of the α, β-unsaturated carboxylic acid alkyl ester of the monomer mixture (A) exceeds the range of the present invention, while Comparative Example 3 is an example below the range of the present invention.

Comparative Example 2 is inferior in transparency to Example 2, and Comparative Example 3 is inferior in impact resistance, which is not preferable.

Comparative Example 4 is a transparent resin currently on the market, which has excellent transparency but low impact resistance.

Methyl methacrylate-styrene copolymer of Comparative Example 4 (MS
(Resin) is a known copolymer and is a transparent resin having excellent optical characteristics, but the resin composition of the present invention does not impair the optical characteristics of MS resin, as is apparent from Table-3. Succeeded in improving the mechanical properties. Further, in Examples 4 and 5, N-cyclohexylmaleimide was copolymerized for the purpose of improving heat resistance, and the heat resistance was significantly improved along with the improvement of mechanical properties. Further, those listed as examples are those in which the refractive index of the copolymer (A) and the copolymer (B) are made to match as much as possible in order to have excellent transparency, but the resin obtained by the present invention The composition, when a coloring agent was added thereto, gave a molded product having a clear color.

The figure also shows an electron micrograph of the molded product obtained in Example 2. As a sample, a molded product was treated at room temperature in a mixed solution of chromic acid and sulfuric acid for 20 hours and used. The magnification is 10,000 times.

According to this photograph, rubber particles having a spherical shape and a particle size of 2000 to 3000 Å are uniformly dispersed, and exhibit a morphology not found in conventional rubber-modified resins. This is because, when the block component is used as a compatibilizer, so-called 0il-in-0il emulsion-like micelle formation, the production condition of the present invention, that is, the condition of reaction in a solution state in continuous steps, acts extremely advantageously. It is thought to be because.

f. Effect of the Invention The resin composition of the present invention has improved mechanical properties without significantly impairing the optical properties by using a special initiator, which is difficult to achieve with conventional transparent resins. It can be used as a large-scale structural material such as injection-molded products and curved plates.

Further, industrially, it is excellent in terms of cost and quality in that a polymer copolymer having an improved compatibility can be obtained by a block copolymer in a continuous process.

Therefore, since the resin composition of the present invention has excellent performance in transparency and weather resistance, it is used for molding materials such as building materials, automobile exterior and interior members, and electrical and electronic parts, medical devices, etc. It provides products, and has an extremely high industrial utility value.

[Brief description of drawings]

 The figure shows an electron micrograph of the molded product obtained in Example 2.

Claims (3)

[Claims] 1. When a polymer is produced from 2 to 40% by weight of the following monomer mixture (A) and 60 to 98% by weight of the following monomer mixture (B), the decomposition temperature varies within one molecule. Using a bifunctional peroxide with two types of peroxy bonds, first, using the peroxy moiety of the bifunctional peroxide that decomposes at low temperature as a catalyst
The monomer mixture of either (A) or (B) is added to carry out the first stage polymerization, and then the temperature is raised to catalyze the peroxy moiety of the bifunctional peroxide that decomposes at high temperature. As
A method for producing a resin composition, which comprises adding a monomer mixture not used in the first step among (A) and (B) and polymerizing the mixture. Monomer mixture (A) α, β-unsaturated carboxylic acid alkyl ester 40 to 98% by weight, aromatic vinyl compound 2 to 60% by weight, and other monomer 0 to 30% by weight copolymerizable therewith A monomer mixture whose copolymer is rubbery. Monomer mixture (B) at least one selected from α, β-unsaturated carboxylic acid alkyl ester and aromatic vinyl compound 60 to 10
0% by weight and other monomers copolymerizable with these 0-40
A monomer mixture which is made up by weight, and whose copolymer has a glass transition point of 60 ° C. or higher. 2. The method for producing a resin composition according to claim 1, wherein the monomer mixture (A) is first polymerized and then the monomer mixture (B) is polymerized. 3. A monomer mixture (B) comprising an α, β-unsaturated carboxylic acid alkyl ester 30 to 100% by weight, an aromatic vinyl compound 0 to 70% by weight, and a monomer 0 copolymerizable therewith.
The method for producing the resin composition according to claim (1), wherein the resin composition is contained in an amount of -40% by weight.