JPS60120734A - Transparent, heat- and impact-resistant resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition which is excellent in transparency and heat, impact and oil resistances and can be inexpensively supplied, by mixing a specified graft copolymer with a matrix polymer. CONSTITUTION:A resin composition comprising 5-50wt% (A) graft copolymer obtained by graft-polymerizing an aromatic vinyl compound and an alkyl methacrylate with a rubber comprising polybutadiene or a butadiene copolymer containing at least 60wt% butadiene units and 95-50wt% (B) matrix polymer which comprises 20-89.5wt% methyl methacrylate units, 5-74.5wt% six-membered ring acid anhydride units of the formula (wherein R1 and R2 are each methyl or H), 5-69.5wt% aromatic vinyl compound units, and 0.5-20wt% (meth)acrylic acid units and which has a viscosity as measured in a 10wt% MEK solution at 25 deg.C of 3-20cP. The refractive index of the copolymer A should be equal to that of polymer B.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a transparent heat-resistant and impact-resistant resin composition, more specifically, a transparent heat-resistant and impact-resistant resin composition, and more specifically, a specific graft copolymer and The present invention relates to an impact-resistant thermoplastic resin composition comprising a matrix polymer.

In recent years, in various applications such as light electrical parts and industrial parts, there has been a particularly strong demand for resins that have excellent heat resistance, impact resistance, and surface resistance to oil, are transparent, and are inexpensive.

Among the resins currently available on the market, Polycarbo Fu-1 is known as a representative resin that is colorless and transparent and has excellent mechanical strength and heat control properties. However, Nakarato resin is an engineering resin and is expensive, so it has not been widely used.

Recently, impact-resistant methyl methacrylate resin (H-nee PMM) has been developed, which maintains the transparency, 11M oiliness and 1IiIt weatherability of methyl methacrylate resin, and adds impact resistance through rubber reinforcement.
A) has begun to be commercially available, but this product has the disadvantage of poor heat resistance.

In addition, transparent MBS resin and transparent ABS resin, which have transparency due to the matching of the refractive index of the kraft copolymer and the refractive index of the matrix polymer, have been commercially available at low cost for a long time, but they have poor thermal properties. Therefore, it has not been widely used.

In addition, by learning the sound of glass fiber, we improved the heat resistance and impact resistance, and by making the refractive index of the glass fiber match the refractive index of the resin, we achieved a fairly transparent heat resistance. Plastic resin gold can be obtained (JP-A-56-
98251). However, the transparency provided by this method is not perfect and has limitations, so it has not been widely used.

Under these circumstances, the present inventors have conducted intensive research to develop a thermoplastic resin composition that has excellent transparency, heat resistance, i'I impact resistance, and oil resistance, and can be supplied at low cost. As a result of stacking, the graft rubber-reinforced resin and a copolymer containing a specific six-membered cyclic acid anhydride unit are combined, and the refractive index of the graft rubber-reinforced resin and the refractive index of the copolymer are realized. :
It was discovered that the objective could be achieved by setting 60 or more units of polybutadiene or butadiene, and based on this knowledge, the present invention was completed. A kraft copolymer obtained by graft polymerizing an aromatic vinyl compound and an argyl methacrylate to a rubber made of a butadiene copolymer containing 5 to 50% weight, and (E) a matrix polymer of 95 to 50% by weight. The matrix polymer consists of (a) 20 to 89.5 methyl methacrylate units, (b) a six-membered compound represented by the general formula (in which R1 and R2 are methyl groups or hydrogen atoms) cyclic acid anhydride unit 5 to 74.5 heavy economy,
(c) A copolymer of 5 to 69.5 units of aromatic vinyl compound and 0.5 to 20 units of acrylic acid or methacrylic acid or both, and -C1 concentration of the matrix portion. The viscosity of a 10% by weight methyl ethyl ketone solution at a temperature of 25° C. is 3 to 20 centiboise, and the Hi refractive index of each of the above-mentioned gelast co-vehicle combination and matrix polymer is above the actual value. The present invention is characterized in that heat resistance and oil resistance are improved by a matrix polymer made of a specific copolymer, and a transparent heat-resistant and impact-resistant resin composition is provided. The object of the present invention is to obtain a resin composition which has improved impact resistance, and which also has improved transparency by adjusting the refractive index of both the matrix polymer and the graft copolymer.

The resin composition thus obtained has the surprising performance of not losing its transparency even when left in hot water at a temperature of 100°C.

Polybutadiene is commonly used as the rubber component for the graph i/copolymer of component (A) in the resin composition of the present invention, and methods for varying the refractive index of this rubber component include: It is preferable to use butadiene as the main component and copolymerize it with other dimers in a random or block manner.In other words, if the refractive index f is higher than that of polybutadiene,
When an aromatic vinyl compound is copolymerized with butadiene and the refractive index is lowered than that of polybutadiene, an acrylic acid alkyl ester or a methacrylic acid alkyl ester may be copolymerized with butanene. In some cases, whole butadiene is copolymerized with unsaturated nitrile monomers.

In order for the thus obtained butadiene copolymer to play a role in increasing the impact resistance of the resin composition of the present invention,
It is necessary that the butadiene unit contained in the meat is at least 60% by weight.・This butadiene unit is 600% by weight.
If the amount is too low, the impact resistance of the resin composition, especially the impact resistance at low temperatures, decreases.

Role of each monomer that undergoes craft polymerization into the rubber component (01J)
d. To improve the affinity between the rubber component and the matrix polymer, and to match the refractive index of the rubber component to the refractive index of the matrix polymer.

The monomers to be graft-polymerized to the rubber component are mainly aromatic vinyl compounds and methacrylic acid alkyl esters, and the preferable proportion of the aromatic vinyl compounds and methacrylic acid alkyl esters is 19% by weight. The range is from 91 to 91.

Examples of the aromatic vinyl compound include styrene, α
-Methylstyrene, p-methylstyrene, etc. are used, and among these, styrene is preferred. Methyl methacrylate is also suitable as the methacrylic acid alkyl ester. In addition, the rubber component
l) In addition to the above-mentioned aromatic vinyl compound and methacrylic acid alkyl ester, one or more other monomers copolymerizable with them are added for the purpose of further improving the affinity for the sox polymer. may be used. However, in this case, the amount of other monomers is 30 parts by weight or more per 100 parts by weight of the above-mentioned aromatic ginyl compound and methacrylic acid alkyl ester. Examples of the copolymerizable monomer include unsaturated nitrides such as acrylonitrile and methacrylonitrile, and unsaturated carboxylic acids such as acrylic acid and methacrylic acid.

The grafting ratio of the thus obtained graft copolymer (core part/stem part weight ratio x 100%) is generally 20%.
-120%, preferably in the range of 30-100%.

In the resin composition of the present invention, the matrix polymer of the Bl component is (a) methyl methacrylate, (b) a six-membered cyclic acid anhydride represented by the general formula +11, and (c)
It is a copolymer consisting of an aromatic vinyl compound unit and/or an acrylic acid or methacrylic acid unit, and has a great influence on the heat resistance, oil resistance, and moldability of the resin composition.

The methyl methacrylate unit (a) in this copolymer plays a role in improving l#j oiliness, and can be contained in a range of 20 to 89.5% by weight in one copolymer. is necessary. If this amount is less than 200% by weight, oil resistance cannot be sufficiently improved;
If it exceeds 5% by weight, the improvement in heat resistance will be insufficient and the moldability will deteriorate.

Next, the six-membered cyclic acid anhydride represented by the general formula (1) of the Naka) unit plays a role in improving heat resistance,
Surprisingly, it has the effect of improving heat deformation resistance and thermal stability at the same time. The content of this (b) unit must be within the range of 5 to 74.5% by weight based on the copolymer. If this amount is less than 5% by weight, the heat deformation resistance and heat stability will deteriorate. The improvement was not sufficient and 74.5% by weight
If it exceeds the above range, the heat-melt viscosity of the resin composition will increase significantly and the molding processability will decrease.

The aromatic vinyl compound unit (c) mainly plays a role in improving moldability, and in this case, the aromatic vinyl compound unit is preferably a styrene unit. In addition, in order to improve heat resistance as well as molding processability, aromatic vinyl compound units, such as α
-methylstyrene/unit, p-methylstyrene unit, 2,
It can also contain 4-dimethylstyrene units and p-tert-butylstyrene units. The content of these aromatic vinyl compound units in the copolymer must be in the range of 5 to 695% by weight. If this amount is less than 5% by weight, the molding force resistance becomes insufficient, which is undesirable, and if it exceeds 69.5% by weight, the oil resistance deteriorates significantly, which is not preferable.

Furthermore, the acrylic acid and/or methacrylic acid units in the unit (b) play a role in improving heat resistance, and in particular, the auxiliary effect of the six-membered cyclic acid anhydride unit in the unit (b). be. The content of this unit in the copolymer ranges from 5 to 20 parts by weight. This amount is 0.5
If it is less than 2% by weight, the role of improving heat resistance by assisting the unit (b) will not be sufficient, and if it exceeds 20% by weight, thermal stability will decrease and gas generation will become significant during molding, which is undesirable.

In this way, each unit of (a), naka), CSI, and n) plays its own role, but at the same time, in order to adjust the refractive index of the Maddox polymer, the combination of the respective amounts is selected as appropriate. be done. For example, when increasing the refractive index of the matrix polymer, the amount of aromatic vinyl compound units is increased, while when decreasing the refractive index, the amount of methyl methacrylate units is increased.

In the resin composition of the present invention, it is necessary to match the refractive index of the graft copolymer of component (a) and the refractive index of the matrix polymer of component (Bl), and the difference in their refractive index is 0.01. In the following cases, the transparency of the resin composition is not excellent, and when the difference is 0.005 or less, the transparency is particularly excellent.

Further, in the resin composition of the present invention, it is necessary that the molecular weight of the matrix polymer of component (B) be within a specific range. That is, the concentration of the matrix polymer is 1
It is necessary that the viscosity of the 0 wt % methyl ether ketone solution at a temperature of 25° C. be within the range of 3 to 20 centipoise. If the viscosity is less than 3 centipoise, the impact resistance of the resin composition will be reduced, and if it exceeds 20 centipoise, the fluidity at high temperature melting will be reduced, resulting in unsatisfactory moldability.

Regarding the production of the resin composition of the present invention, any ordinary radical polymerization method can be used, but it is particularly preferable to produce the kraft copolymer (A) component by an emulsion polymerization method. It is particularly desirable to produce the matrix polymer by a continuous bulk polymerization method.Furthermore, the polymerization vessel is preferably of a complete mixing type in order to ensure uniformity of each male unit in the matrix polymer.The graft copolymer The emulsion polymerization method is preferably used for the production of the polymer, but the bulk polymerization method can also be used. (When obtaining the A + acid component kraft copolymer by an emulsion polymerization method, the kraft copolymer 11 as a solid is first melt-mixed with the matrix polymer copolymer solid of the Bl component, Finally, the desired resin composition (i-) is obtained. In this case, a single-screw or twin-screw extruder is usually used.

The resin composition thus obtained is a blend of a kraft copolymer and a matrix polymer, and by utilizing the fact that the rubber phase forms a crosslinked body, the graft copolymer is used as an acetone-insoluble part. , can be separated from the acetone-soluble matrix polymer. In this case, 1
First, the resin composition is made into a powder, acetone is added thereto, and the powder is thoroughly shaken, and then an insoluble part and a soluble part are separated using a centrifuge. Next, acetone is added to the insoluble portion and the above operation is repeated. Since the finally obtained insoluble portion contains acetone, it is sufficiently dried in a vacuum dryer at room temperature and then weighed. On the other hand, the acetone-soluble portion can be obtained as a residue by evaporating acetone.

After measuring the weight of each part, it is possible to measure the loaf yield and analyze the composition of each part. In particular, it is desirable to quantitatively analyze the composition of the acetone 5T molten part by the following method.

That is, for an acetone solution of a constant concentration, the unit amount of acrylic acid or methacrylic acid, or both, can be measured by caustic alkaline titration, and the aromatic vinyl compound unit (it) can be determined by using an external absorption spectrophotometer. Further, the amount of methyl methacrylate units and the amount of six-membered cyclic acid anhydride units are measured by infrared spectroscopy at 110%. 1800 crn- of six-membered cyclic acid anhydride units
' and absorption of 1760α-1 (distinguished from those of other carbonic acid units and carboxylic acid ester units).

The transparent surface of the present invention has 111t impact strength and oil resistance equivalent to ABS resin and MBS resin, and has excellent transparency and significantly improved heat resistance. Furthermore, it has overall excellent characteristics, such as significantly lower decomposition when melted at high temperatures and no whitening or devitrification even in hot water.

EXAMPLES Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples in any way.

In addition, the measurement method of each physical property in an Example is the reverse of the following.

(1) Vikatsu softening temperature load IK9ASTM-D1
525 (2) Izot impact strength ASTM-D 25
6(7) Refractive index Measured according to AS'l'M D 542 Reference example 1 Production of graft copolymer (A-1) Styrene consisting of 35.5% by weight of styrene units and 64.5% by weight of butadiene units 60 parts by weight of butadiene rubber (IEBR) latex in terms of solid content and 10 parts by weight of ion-exchanged water
0 parts by weight were placed in a reactor, and while stirring, at 70°C, a mixture of 20 parts of methylene chloride and 20 parts of methyl ivy acrylate and 0.1 parts by weight of potassium persulfate were added to 50 parts by weight of ion-exchanged water. Polymerization was carried out while continuously adding the dissolved aqueous solution for 7 hours, and after the polymerization reaction was completed, the kraft copolymer latex was salted out, dehydrated, and dried to obtain a powdery ground copolymer (A-1). Ta.

The refractive index of this graft copolymer (A-1) was measured and found to be 1.544 ◇ Reference Example 2 Production of kraft copolymer (A-2) Styrene units 10 heavy economic conditions, butadiene units 90 M% A reactor was charged with 60 parts by weight of styrene-butadiene rubber (sBR) latex (converted to solid content) and 100 parts by weight of ion-exchanged water, and styrene 1
A mixture of 2 parts by weight and 28 parts by weight of methyl methacrylate and 0.1 parts by weight of potassium persulfate were dissolved in 50 parts by weight of ion-exchanged water. This was followed by post-treatment to obtain a powdered kraft copolymer (A-2).

The refractive index of this graft copolymer (A-2) was measured and found to be 1.520.

Example 1 Methyl methacrylate 3'1.2 parts by weight, styrene 34.
3 parts by weight, 8.5 parts by weight of methacrylic acid, 20 parts by weight of toluene, 0 parts by weight of octyl mercaptaf.
．． A mixed solution is prepared by adding 0.05 parts by weight of 0.05 parts by weight and 0.01 parts by weight of 1,1 tertiary butyl peroxin chlorohexane. This mixed solution was continuously supplied to a complete mixing type polymerization vessel at 112° C. for polymerization. A polymerization reaction solution having a solid content of 42% by weight was continuously supplied to a high-temperature vacuum chamber to remove unreacted substances and solvent and to produce a six-membered cyclic acid anhydride. Analysis of the composition of the obtained copolymer revealed that methyl methacrylate units were 40% by weight, styrene units were 43% by weight, six-membered cyclic acid anhydride units were 15% by weight, and methacrylic acid units were 2% by weight.

Also, the refractive index of this copolymer is 1.542.
The viscosity at 25°C of a 0 weight methyl ethyl ketone solution is 10
．． It was 0 centipoise.

The softening temperature of a compression molded piece of this copolymer is 129
It was ℃. 70 parts by weight of this copolymer and 30 parts by weight of the graft copolymer (A-1) were blended, mixed and extruded using a twin-screw extruder and pelletized.

The external shape of this resin composition is shown in the attached table.

Example-2 Methyl methacrylate 28 parts i=b, 13 parts by weight of styrene, 24 parts by weight of methacrylic acid, 4 parts by weight of ethylene glycol monoethyl ether, g4 parts by weight, 0.1 parts by weight of octyl mercaptan , 1, ]-G-
A mixed solution was prepared by adding 0.01 part by weight of tertiary butyl peroxide/-3,3°5-trimethylcyclohexane to 11 parts by weight. Other than that, polymerization was carried out in exactly the same manner as in Example 1 to obtain a copolymer. The composition of the obtained copolymer was analyzed and found to be 30 parts by weight of methyl methacrylate units, 26 parts by weight of styrene units, 36 parts by weight of six-membered cyclic acid anhydride units, and 8 parts by weight of methacrylic acid units. In addition, the refractive index (;il', 521) of this copolymer was 68 centipoise at 25°C of a solution of this copolymer in 10% methyl ethyl ketone. The Vikatsu softening temperature was 148° C. 70 parts by weight of this copolymer and 30 parts by weight of Kraft copolymer (A-2) were blended, kneaded, extruded, and pelletized using a twin-screw extruder. The properties of this resin composition are shown in the attached table.

Comparative Example: 40 parts by weight of methyl methacrylate, 40 parts by weight of styrene,
Example 1: chain transfer agent, polymerization initiator, and other polymerization conditions 1!
Polymerization was carried out in exactly the same manner as above to obtain a copolymer. A complete compositional analysis of the obtained copolymer revealed that 5 methyl methacrylate units
() It was heavy and the styrene unit was 50th power.The refractive index of this material was 1540. A compression-molded piece of this copolymer had a Vicat softness ratio l'' of 1110°C.
A resin composition was obtained in the same manner as in Example 1. The properties of this material are shown in the attached table.

As shown in the attached table, the resin composition according to the present invention is a transparent and hard-acting resin composition with excellent thermal deformability and heat resistance stability, and is also stable against hot water and oil resistant. It has excellent overall quality, including excellent quality.

Claims (1)

[Scope of Claims] 1(A) A kraft copolymer obtained by graft polymerizing an aromatic vinyl compound and an argyl methacrylate to a rubber made of polybutadiene or a butadiene copolymer containing 60 or more weight units of butadiene units. (B) 95 to 50% by weight of a matrix polymer, (a) 20 to 89.5% by weight of methyl methacrylate units, (b) general formula ( 5 to 74.5% by weight of six-membered cyclic acid anhydride units represented by (wherein R1 and R2 are methyl groups or hydrogen atoms);
(c) A copolymer comprising 5 to 695% by weight of aromatic vinyl compound units and 0.5 to 20% by weight of acrylic acid or (methacrylic acid) units, wherein the concentration of the matrix polymer is A transparent heat-resistant material characterized in that a 10% by weight methyl ethyl ketone solution has a viscosity of 3 to 20 centiboise at a temperature of 25°C, and the refractive index of the kraft copolymer and the matrix polymer are substantially the same. Impact resin composition.