JP3310362B2 - Impact resistant resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact-resistant resin composition, and more particularly to a methacrylic impact-resistant resin composition in which the occurrence of spots is remarkably improved without impairing transparency and weather resistance.

[0002]

2. Description of the Related Art Methacrylic resin is colorless and transparent, has a beautiful appearance and weather resistance, and is easy to mold. Therefore, electric parts such as louvers, tail lamps, lenses, tableware, vehicle parts, optical applications, decoration, miscellaneous goods, Although widely used for signboards, the strength against impact is not always sufficient, and many improvements and modifications have been studied, and the resin has been commercialized as a methacrylic impact-resistant resin. However, although these commercially available methacrylic impact-resistant resins satisfy the intended impact resistance as such, the impact modifier added and mixed with the general-purpose methacrylic resin is not completely compatible, but in the form of particles. Because of the dispersion, the presence of agglomerates or coagulates of the particles is the cause of lumps.Especially, a small amount of lumps are observed as lumps on the surface during sheet molding or thin film, and it is still satisfactory. There are no products available.

[0003]

SUMMARY OF THE INVENTION The present invention relates to an impact-resistant resin composition having good transparency and weather resistance, and significantly improved generation of bumps in injection molded articles, sheets and films. It is intended to provide an impact modifier.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies on a methacrylic impact-resistant resin having good transparency and weather resistance and significantly improved generation of bumps, and as a result obtained by emulsion polymerization. After uniformly mixing in a latex state two or more multilayered polymers having specific different particle diameters and a hard thermoplastic polymer having a specific particle diameter, they have good transparency and weather resistance by coagulation. The present inventors have found that the occurrence of bumps is remarkably improved, and have completed the impact-resistant resin composition and the impact-resistance improving agent of the present invention.

[0005] That is, the present invention relates to a method for producing particles having a particle size of
0 to 90 parts by weight of a multilayer structure polymer (A) having a particle size of 1 to 90 parts by weight, and 1 to 90 parts by weight of a multilayer structure polymer (B) having a particle size of 0.01 μm or more and less than 0.10 μm.
0.5 to 90 parts by weight of the hard thermoplastic polymer (C) having a particle size of 0.50 μm, and between the amount (b) of the component (B) and the amount (c) of the component (C), 0.5 (B) + (c) ≧ 10 (1) An impact-resistant resin composition obtained by uniformly mixing (A), (B), and (C) in a latex state within a range that satisfies , (A) and (B) are 50 to 99.9% by weight of a mixture of a diene monomer and at least one alkyl acrylate having 1 to 8 carbon atoms in an alkyl group;
Emulsifying a monomer mixture consisting of 0 to 49.9% by weight of an unsaturated monomer copolymerizable therewith, a polyfunctional crosslinking monomer and / or 0.1 to 5% by weight of a polyfunctional graft monomer. At least one soft polymer layer having a glass transition temperature of 25 ° C. or lower formed by polymerization, and having 1 to 4 carbon atoms in the alkyl group.
At least one alkyl methacrylate which is 4
0-100% by weight, a monomer mixture comprising 0-50% by weight of an unsaturated monomer copolymerizable therewith, a polyfunctional crosslinking monomer and / or 0-5% by weight of a polyfunctional graft monomer At least one alkyl methacrylate having a combination of at least one hard polymer layer having a glass transition temperature of 25 ° C. or higher, wherein the outermost layer has an alkyl group having 1 to 4 carbon atoms. 25.degree. C. obtained by emulsion polymerization of a monomer mixture comprising 50 to 100% by weight and 0 to 50% by weight of an unsaturated monomer copolymerizable therewith, wherein the ratio of the outermost layer to the total amount is 10 parts by weight or more. It is a multilayer polymer comprising a hard polymer layer having the above glass transition temperature, and (C) has an alkyl group having 1 carbon atom.
At least one alkyl methacrylate 5
0-100% by weight, and a rigid thermoplastic polymer obtained by emulsion polymerization of a monomer mixture comprising 0-50% by weight of an unsaturated monomer copolymerizable therewith).

In the present invention, the particle diameter of the multi-layered polymer is 0.10 to 0.50 μm, which is not less than 0.01 μm and 0.10 μm.
Although divided into less than m, for obvious reasons exist for this. When the weight ratio of the soft polymer layer in the multilayer polymer is the same, the particle size of the multilayer polymer is not more than 0.10 μm, and when the weight ratio is higher, the impact strength is high even when the blend ratio of the multilayer polymer is small. On the other hand, the dispersibility from the coagulated material to the particles is poor, and there is a tendency that lumps are likely to occur. On the other hand, when the particle diameter is less than 0.10 μm, the dispersibility from the coagulated material to the particles is good and the occurrence of bumps is small, but when the blend ratio of the multilayer structure polymer is large, there is no particular problem, but when the blend ratio is reduced. There is a contradictory tendency that the impact strength sharply decreases.

[0007] Therefore, as a result of investigations by the present inventors, the present invention can provide an impact strength commensurate with a low blend ratio of a multi-layered polymer and extremely little occurrence of bumps in a wide particle diameter range. An object of the present invention is to provide an impact resin composition and an impact modifier. That is, the impact-resistant resin composition of the present invention, which has good transparency and weather resistance and has significantly improved generation of bumps, and an impact-resistance improving agent, have a multilayer structure having a particle diameter of 0.10 to 0.50 μm. 10 to 90 parts by weight of a polymer (A), 1 to 90 parts by weight of a multilayer structure polymer (B) having a particle size of 0.01 μm or more and less than 0.10 μm , and hard heat having a particle size of 0.01 to 0.50 μm A thermoplastic polymer (C) consisting of 1 to 90 parts by weight, and (B)
(B) parts by weight and (c) parts by weight of (C), each was uniformly mixed in a latex state within a range satisfying 0.5 (b) + (c) ≧ 10 (1) Later it was found to be obtained by coagulation.

The particle size of the multilayer polymer (A) of the present invention is preferably 0.10 to 0.50 μm, more preferably 0.15 to 0.5 μm.
When the particle diameter is more than 0.50 μm, the occurrence of bumps increases rapidly, which is not preferable. The addition amount is 10
When the amount is less than 10 parts by weight, a suitable impact strength cannot be obtained, and when the amount exceeds 90 parts by weight, bumps are liable to occur and the weather resistance is undesirably lowered. The particle diameter of the multilayer polymer (B) is 0.01 μm or more and 0.10 μm.
Less, more preferably 0.05 to 0.08 μm,
If it is less than 0.01 μm, not only does the impact strength not increase, but also does not decrease. The addition amount is 1 to 90 parts by weight,
If the amount exceeds the weight part, there is a region where the impact strength is not increased by blending with a general purpose methacrylic resin as an impact resistance improving agent, which is not preferable. The particle size of the hard thermoplastic polymer (C) is 0.1.
01 to 0.50 μm, more preferably 0.05 to 0.25
μm, and when the particle size is less than 0.01 μm, the particles do not decrease, and when the particle size is 0.50 μm or more, the particles do not decrease. The addition amount of the hard thermoplastic polymer (C) is 1 to 90 parts by weight,
If the amount exceeds the weight part, the impact strength decreases, which is not preferable.

In a latex blend of the multilayer polymers (A) and (B) and the rigid thermoplastic polymer (C),
In the combination of (A) and (B), and in the combination of (A) and (C), the number of particles is reduced. However, the result is not obtained by the reduction of the number of particles that satisfy the present invention. In the combination of (B) and (C), the number of particles is reduced. Although good results can be obtained for (B), when the blend ratio of (B) is small, the impact strength sharply decreases, and the present invention is satisfied only by the combination of (A), (B) and (C). Further, in addition to the combination of (A), (B) and (C), [one or more (A)], [one or more (B)] and [one The combination of the above (C)] is also possible. Further, the composition and the layer structure of the multilayer polymer (A) and the multilayer polymer (B) do not need to be the same.

[0010] The impact-resistant resin composition and the impact modifier of the present invention are obtained by mixing a multilayer structure polymer (A), (B) and a hard thermoplastic polymer (C) in a latex state obtained by emulsion polymerization. It is characterized by being obtained by coagulation after uniform mixing.

The emulsion polymerization for obtaining the multilayer structure polymer and the rigid thermoplastic polymer of the present invention is carried out by a known method. The type and amount of the emulsifier used for the emulsion polymerization are selected depending on the stability of the polymerization system, the intended particle size, and the like.
Known emulsifiers such as anionic surfactants, cationic surfactants, and nonionic surfactants can be used alone or in combination, and anionic surfactants are particularly preferred. The polymerization initiator used for the emulsion polymerization is not particularly limited, and a persulfate-based or redox-based initiator is used. A chain transfer agent such as an alkyl mercaptan is used as needed.

In emulsion polymerization, a monomer, an emulsifier, a polymerization initiator, a chain transfer agent and the like are added by any method such as a batch addition method, a division addition method and a continuous addition method.

The method of uniformly mixing and precipitating and solidifying the respective polymer latexes obtained by emulsion polymerization is not particularly limited, and a salting out method, an acid precipitation method, a spraying method, a freezing method and the like can be used.

The multilayer polymer of the present invention has at least one polymer.
It comprises at least one soft polymer layer and at least one hard polymer layer, and the outermost layer is a hard polymer layer. The soft polymer layer in the multilayer polymer has a mixture of a diene monomer and at least one alkyl acrylate having an alkyl group having 1 to 8 carbon atoms in an amount of 50 to 99.9% in terms of impact resistance and weather resistance. % As a main monomer, and 0 to 49.9% by weight of an unsaturated monomer copolymerizable therewith,
It is composed of a polyfunctional crosslinkable monomer and / or a polyfunctional graft monomer in an amount of 0.1 to 5% by weight, and has a glass transition temperature of 25 ° C or lower when a monomer mixture thereof is polymerized alone.

The diene monomers used for the soft polymer layer include 1,3-butadiene, 2,3-butadiene and isoprene, and the alkyl acrylates include methyl acrylate, ethyl acrylate, n-butyl acrylate, and the like. Examples thereof include i-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and benzyl acrylate, which are used alone or in combination. As unsaturated monomers copolymerizable therewith, styrene, α-methylstyrene, vinyltoluene,
Methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, acrylonitrile, methacrylonitrile, phenylmaleimide, N-cyclohexylmaleimide, N-methylmaleimide, etc. are used alone or in combination. As the polyfunctional crosslinking monomer, ethylene glycol di (meth) acrylate,
1,3-butylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, divinylbenzene, etc., and polyfunctional graft monomers include allyl methacrylate, allyl acrylate, allyl maleate, allyl fumarate, diallyl Examples thereof include fumarate and triallyl cyanurate, which are used alone or in combination.

The hard polymer layer of the multilayer polymer has an alkyl group having 1 to 4 carbon atoms in terms of transparency and weather resistance.
At least one alkyl methacrylate of 50 to 10
0% by weight is used, particularly preferably methyl methacrylate. The monomers copolymerizable therewith are 0 to 50% by weight of an unsaturated monomer, 0 to 5% by weight of a polyfunctional crosslinkable monomer and / or a polyfunctional graft monomer,
All the monomers used in the soft polymer layer containing the alkyl acrylate can be used, and when these monomer mixtures are polymerized alone, they have a glass transition temperature of 25 ° C. or more.

The outermost layer of the multi-layered polymer comprises a hard polymer layer having a glass transition temperature of 25 ° C. or more in view of compatibility with general-purpose methacrylic resin, and the ratio of the outermost layer to the total amount is 10 parts by weight. That is all. As the monomer constituting the outermost layer, at least one alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms is used in an amount of 50 to 100% by weight from the viewpoint of transparency and weather resistance, as in the case of the hard polymer. Particularly preferred is methyl methacrylate. The monomer copolymerizable therewith is 0 to 50% by weight of an unsaturated monomer, and is used in the hard polymer layer excluding a polyfunctional crosslinkable monomer and a polyfunctional graft monomer. All the monomers mentioned can be used. Furthermore, n-octyl mercaptan, n-
A chain transfer agent such as dodecyl mercaptan is preferably used.

The multilayer structure polymer of the present invention can be obtained as a polymer latex by successively emulsion-polymerizing the monomer mixture of each of these layers.

The multilayer structure polymer of the present invention has a multilayer structure polymer (A) having a particle size of 0.10 to 0.50 μm and a multilayer structure having a particle size of 0.01 μm or more and less than 0.10 μm depending on the difference in particle size. Combined (B), both of which satisfy the above composition and structure, but need not have the same composition and structure.

The rigid thermoplastic polymer (C) of the present invention has an alkyl group having 1 to 4 carbon atoms in terms of transparency and weather resistance.
At least one alkyl methacrylate 50 to
100% by weight, particularly preferably methyl methacrylate. The monomer copolymerizable therewith is an unsaturated monomer in an amount of 0 to 50% by weight, and excluding the polyfunctional crosslinkable monomer and the polyfunctional graft monomer. All monomers used in the polymer layer can be used. Furthermore, n-octyl mercaptan, n-octyl mercaptan,
-A chain transfer agent such as dodecyl mercaptan is preferably used. Further, the rigid thermoplastic polymer (C) is obtained by emulsion polymerization of these monomer mixtures, and has a particle diameter of 0.01 to
It is a 0.50 μm polymer and is obtained as a polymer latex.

The impact-resistant resin composition of the present invention comprises a coagulated powder obtained by coagulating the above polymer latex mixture, a mixture of different coagulated powders, a mixture of the coagulated powder and a methacrylic resin, or Any of these pellets and the like may be used, and they are processed directly into sheets and films by an extruder as an injection molding material.

The impact-resistant resin composition is also very effective as an impact-resistance improving agent. Here, the impact resistance improver may be any of a coagulated powder, a mixture of different coagulated powders, and a mixture of a coagulated powder and a methacrylic resin, or a pellet thereof, or the like. A material which imparts impact resistance by blending with a resin and gives an arbitrary methacrylic resin composition.

In the resin composition of the present invention, ultraviolet absorbers, antioxidants, lubricants, dyes and pigments which are usually used for methacrylic resins can be added as required.

The injection-molded articles, sheets and films obtained by using the impact-resistant resin composition of the present invention and the impact-resistance improving agent, and their processed products have good transparency and weather resistance as well as impact resistance. And the occurrence of bumps is remarkably improved.

[0025]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.
In the examples, “%” and “parts” are all “% by weight”.
And "parts by weight", and the following abbreviations are used for monomers, polymerization initiators, chain transfer agents and the like. Methyl methacrylate (MMA), methyl acrylate (MA), ethyl acrylate (EA), n-butyl acrylate (BA), isoprene (IP), 1,3-butadiene (BD), styrene (ST), allyl methacrylate (ALMA) , 1,3-butylene glycol dimethacrylate (BGDMA), n-octyl mercaptan (n-OM), sodium stearate (SS), N
-Sodium lauroyl sarcosinate (LSS), potassium persulfate (KPS).

The horizontal line (-) is used to separate monomers and the like used to form the same layer.
Means that the layers are different.

The occurrence of bumps from the methacrylic impact resistant resin composition in the examples and the resin composition obtained by the methacrylic impact modifier was evaluated by extruding a 50φ sheet with three mirror-finished rolls. Prototype 3mm extruded plate with
The surface condition of the extruded plate was evaluated according to the following classification. Very many spots ... × × There are spots ... × Almost no spots ... △ No spots ... ○ Evaluation of the physical properties of the resin compositions and the like in the examples was measured according to the following methods. (1) Heat deformation temperature; HDT ASTM-D
648 (264 psi) (2) Izod impact strength (with notch) ASTM-D
256 (3) Total light transmittance, haze ASTM-D
1003 (3mm thickness) (4) Particle size Measured by electron microscope. (5) Weather resistance test Accelerated exposure test,
Exposure time 1000 hrs (Sunshine weather meter) Izod impact strength and haze were evaluated. Example 1 (1) Production of multilayer polymer (A-1) latex In a pressure-resistant reaction vessel equipped with a reflux condenser, ion-exchanged water 140 was added.
Part, SS0.2 part, LSS0.1 part, MMA18 part, M
A1 part, ALMA 0.01 part, then KPS
0.1 part was added, and the inside of the pressure-resistant reaction vessel was replaced with nitrogen.
The temperature was raised to ℃, and polymerization was carried out for 30 minutes.

Then, in the presence of this latex, BA3
6 parts, diisopropylbenzene hydroperoxide 0.15 part, sodium pyrophosphate 0.4 part, ferrous sulfate 0.005 part, dextrose 0.2 part, and BD
24 parts were charged, the temperature was increased to 70 ° C. by pressurization, and polymerization was performed for 2 hours.

Next, the obtained latex was cooled to 55 ° C., and then KPS (0.03 part) was added.
A1 part and a monomer mixture consisting of 0.05 part of n-OM were mixed in 9 parts.
It was added continuously over 0 minutes, and maintained for 60 minutes after completion of the addition to complete the polymerization to obtain a multilayer polymer (A-1) latex. After the polymerization of each layer was completed, the latex was sampled, and it was confirmed by an electron microscope observation that no new particles were generated and the sequential polymerization was completely performed. The particle size of the obtained latex was 0.21 μm. The composition of this latex corresponds to (A-1) in Table 1. (2) Production of Multilayered Polymer (B-1) Latex As in the case of the multilayered polymer (A-1), 140 parts of ion-exchanged water, 0.5 part of SS and LS were placed in a pressure-resistant reaction vessel equipped with a reflux condenser.
S 1.5 part, then BA 45 part, ALMA 0.3 part, diisopropylbenzene hydroperoxide 0.15
Parts, sodium pyrophosphate 0.4 parts, ferrous sulfate 0.0
05 parts, dextrose 0.2 parts, and BD 25 parts were further charged, and the inside of the pressure-resistant reaction vessel was replaced with nitrogen.
The temperature was raised to ℃, and polymerization was carried out for 2 hours.

Next, the obtained latex was cooled to 55 ° C., and 0.04 parts of KPS was added.
A monomer mixture consisting of 2 parts and 0.05 part of n-OM was mixed with 40 parts of
After the addition, the mixture was kept for 60 minutes after completion of the addition to complete the polymerization to obtain a multilayer polymer (B-1) latex. After the polymerization of each layer is completed, latex is sampled,
It was confirmed by electron microscopy that no new particles were generated and complete sequential polymerization was performed. The particle size of the obtained latex was 0.07 μm. The composition of this latex corresponds to (B-1) in Table 1. (3) Production of a hard thermoplastic polymer (C-1) latex As in the case of the multilayer polymer (A-1), 250 parts of ion-exchanged water and 1 part of LSS are charged into a reaction vessel equipped with a reflux condenser and stirred under a nitrogen atmosphere. While heating to 80 ° C, MM
47.5 parts of A, 2.5 parts of MA and 0.05 parts of KPS were charged and reacted for 60 minutes to complete the polymerization. Then KPS
When 0.05 parts were charged, 47.5 parts of MMA, MA
A monomer mixture consisting of 2.5 parts was continuously added dropwise for 60 minutes, the whole amount was charged, and the mixture was held for 60 minutes to complete the polymerization.
The particle size of the obtained latex was 0.14μ. The composition of this latex corresponds to (C-1) in Table 1.

Each of the polymer latexes thus obtained was converted to a polymer having a multilayer structure (A-1).
50 parts, 40 parts of the multilayer structure polymer (B-1) and 10 parts of the hard thermoplastic polymer (C-1) were uniformly mixed in a latex state, and then added to a 3% aluminum chloride aqueous solution to carry out salting out coagulation, After washing with water and drying, a polymer powder was obtained. 100 parts of the polymer powder thus obtained and 100 parts of extrusion molding grade and parapet EH beads were mixed by a supermixer, extruded by a sheet extruder, and evaluated for various properties including buttocks. Table 2 shows the results. Examples 2 to 9 In the same manner as in Example 1, multilayer polymers (A-2) to (A-4) having different numbers of layers, compositions and particle diameters, and a multilayer polymer (B-2) -(B-3) latex and hard thermoplastic polymer (C-2)-(C-
3) A latex was obtained. Table 1 shows the number of layers, composition, and particle size of these polymers.

The mixing ratio of each polymer in the latex blend, the mixing ratio of general-purpose methacrylic resin during sheet extrusion,
Table 2 shows the evaluation results of the obtained extruded plates. No exudates were observed in the extruded plates obtained in these examples, and various physical properties satisfying the present invention including the Izod impact strength were obtained. Injection molded articles made of pellets having the same composition as these extruded plates also showed the same results as the extruded plates.

The methacrylic resin used in the blending when extruding the polymer powder with a sheet extruder in the examples is shown in Table 1. Comparative Examples 1 to 9 Although the multi-layered polymer latex and the hard thermoplastic polymer latex in the examples were used, not only appeared but also satisfactory ones could not be obtained.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

Industrial Applicability According to the present invention, an impact-resistant resin composition having good transparency and weather resistance, and significantly improved generation of bumps in injection molded articles, sheets, films, and the like, and improved impact resistance Agent is obtained.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 51/00 C08L 33/10

Claims (4)

(57) [Claims] 1. 10 to 90 parts by weight of a multilayer polymer (A) having a particle size of 0.10 to 0.50 μm, and a particle size of 0.01 μm.
m to less than 0.10 μm multilayer polymer (B) 1 to 9
0 parts by weight, and 1 to 90 parts by weight of the hard thermoplastic polymer (C) having a particle size of 0.01 to 0.50 μm, and the amount of (B) (b) and the amount of (C) ( c) After uniformly mixing (A), (B) and (C) in a latex state within a range satisfying 0.5 (b) + (c) ≧ 10 (1) with the weight part, coagulation An impact-resistant resin composition obtained by the above method. However, (A) and (B) are 50 to 99.9% by weight of a mixture of a diene monomer and at least one alkyl acrylate having 1 to 8 carbon atoms in an alkyl group;
Emulsifying a monomer mixture consisting of 0 to 49.9% by weight of an unsaturated monomer copolymerizable therewith, a polyfunctional crosslinking monomer and / or 0.1 to 5% by weight of a polyfunctional graft monomer. At least one soft polymer layer having a glass transition temperature of 25 ° C. or lower formed by polymerization, and having 1 to 4 carbon atoms in the alkyl group.
At least one alkyl methacrylate which is 4
0-100% by weight, a monomer mixture comprising 0-50% by weight of an unsaturated monomer copolymerizable therewith, a polyfunctional crosslinking monomer and / or 0-5% by weight of a polyfunctional graft monomer At least one alkyl methacrylate having a combination of at least one hard polymer layer having a glass transition temperature of 25 ° C. or higher, wherein the outermost layer has an alkyl group having 1 to 4 carbon atoms. 25.degree. C. obtained by emulsion polymerization of a monomer mixture comprising 50 to 100% by weight and 0 to 50% by weight of an unsaturated monomer copolymerizable therewith, wherein the ratio of the outermost layer to the total amount is 10 parts by weight or more. It is a multilayer polymer comprising a hard polymer layer having the above glass transition temperature, and (C) has an alkyl group having 1 carbon atom.
At least one alkyl methacrylate 5
It is a rigid thermoplastic polymer obtained by emulsion polymerization of a monomer mixture of 0 to 100% by weight and 0 to 50% by weight of an unsaturated monomer copolymerizable therewith. 2. The impact-resistant resin composition according to claim 1, wherein the diene monomer is butadiene or isoprene. 3. The impact-resistant resin composition according to claim 1, wherein the alkyl methacrylate unit is a methyl methacrylate unit. 4. A resin composition obtained by using the impact-resistant resin composition according to claim 1 as an impact modifier and blending it with a methacrylic resin.