JPS6250359A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To prevent moldings from causing a delamination phenomenon and to improve environmental stress cracking resistance, by mixing a rubber-contg. styrene resin with a copolymer. CONSTITUTION:The titled compsn. is formed by mixing 100pts.wt. rubber-contg. styrene resin (A) with 1-50pts.wt. copolymer (B). Component B is obtd. by copolymerizing 100pts.wt. vinyl ester of a fatty acid or mixture thereof with other copolymerizable monomer and 0.01-10pts.wt. bifunctional long-chain monomer of formula I [wherein R<1>, R<2> are each H, CH3; X is a group of formula II (wherein n is an integer of at least 2; R<3> are the same or different groups and each is H, CH3)]. The copolymer must have a solubility parameter of 8.4-9.8(cal/cc)<1/2>, a glass transition temp. of 20 deg.C or below and a gel content of 70wt% or below.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thermoplastic resin composition that has excellent environmental stress resistance and improved laminar peelability.

[Conventional technology]

When rubber-containing styrenic resins come into contact with chemicals under stress, cracks occur and, in severe cases, breakage is observed. This phenomenon is called environmental stress cracking phenomenon.
It is well known that this phenomenon is significantly observed in chemicals such as alcohols, carboxylic acids, esters, alkanes, and alkenes that do not have high solubility in resins.

Environmental stress cracking phenomenon is caused by the distortion that remains inside the molded product even when no external force is applied to the resin molded product.
This is caused by the release of rubber when it comes into contact with chemicals, which greatly limits the applications of rubber-containing styrenic resins.

The content of the rubber component and the molecular weight of the resin component are known factors that affect the environmental stress cracking properties of rubber-containing styrenic resins. Although it is possible to improve the environmental stress cracking resistance by increasing the ratio, the effect was insufficient for practical use.

Recently, the present inventors have discovered that the environmental stress cracking resistance of rubber-containing styrenic resins can be dramatically improved by mixing fatty acid vinyl ester polymers with rubber-containing styrenic resins. (Unexamined Japanese Patent Publication No. 147841/1984)
.

However, although the composition of the invention has a remarkable effect of improving environmental stress cracking resistance, a mica-like layered peeling phenomenon is sometimes observed in injection molded products, and improvements have been sought. The delamination phenomenon is noticeable in molded products injection molded under high shear rate conditions, and is noticeable near the gate.

The delamination phenomenon occurs when the fatty acid vinyl ester polymer particles dispersed in the rubber-containing styrene resin undergo flattening deformation due to shear stress during injection molding. For the purpose of preventing flattening of fatty acid vinyl ester polymer particles, it is effective to copolymerize a polyfunctional vinyl monomer during polymerization of the fatty acid vinyl ester polymer.

[Problem that the invention seeks to solve]

However, fatty acid vinyl ester polymers obtained by copolymerizing polyfunctional vinyl monomers such as divinylbenzene and ethylene glycol dimethacrylate,
Although the delamination phenomenon is improved, the gel content is high and the effect of improving the environmental stress cracking property of rubber-containing styrenic resin is insufficient. For this reason, it is necessary to use a polyfunctional vinyl monomer and a chain transfer agent in combination to produce a fatty acid vinyl ester polymer with a low gel content and a branched structure. Although it is possible to measure the balance of stress cracking resistance, the effect is unsatisfactory in practical terms.

An object of the present invention is to provide a thermoplastic resin composition that improves the drawbacks of the prior art described above.

[Means for solving problems]

To summarize the present invention, the present invention relates to a thermoplastic resin composition, comprising (4) a rubber-containing styrene resin and (
B) A thermoplastic resin composition containing 1 to 50 parts by weight of component (B) per 100 parts by weight of component (A), wherein the copolymer of component (B) is added to 100 parts by weight of a fatty acid vinyl ester monomer or a mixture of a fatty acid vinyl ester monomer and another copolymerizable monomer, and the following general formula I: [wherein R1 and R3 are H or OH3 group, is +an, -
cnR3-o←CH0HR''- group (n is an integer of 12 or more, R3 is the same or different C, H or ans group) long chain bifunctional monomer represented by body Q, 0
It is obtained by copolymerizing 1 to 10 parts by weight, has a solubility parameter of a4 to 98 (oaL/cc)h, a glass transition temperature of 20°C or less, and a gel content of 701
i% or less.

The resin composition of the present invention has excellent environmental stress cracking resistance and is less likely to cause delamination.

Monomers constituting the rubber component of the rubber-containing styrenic resin, which is component (A) in the present invention, include butadiene,
Conjugated diene monomers such as inbrene, dimethylbutadiene, chloroprene, cyclopentadiene, non-conjugated diene monomers such as 2,5-norbornadiene, 1,4-cyclohexadiene, 4-ethylidene norbornene, styrene, α-methyl Styrenic monomers such as styrene and vinyltoluene; nitrile monomers such as acrylonitrile and methacrylonitrile; There are olefin monomers such as styrene, phlopylene, 1-butene, imbutylene, and 2-butene, and homopolymerization or copolymerization of these monomers is used.Also, polyfunctional vinyl monomers are used as crosslinking monomers. A copolymer obtained by copolymerizing a polyfunctional vinyl monomer can also be used, but the polyfunctional vinyl monomer that can be used is
L/y glycol dimethacrylate), 1.3-butylene glycol dimethacrylate, 1.4-butylene glycol dimethacrylate, propylene glycol dimethacrylate, triallyl quanurate, triallyl isonanurate, trimethylolpropane trimethacrylate, allyl acrylate, allyl Examples include methacrylate, vinyl acrylate, vinyl methacrylate, glycidyl acrylate, and glycidyl methacrylate.

The rubber component used in component (A) of the present invention must have a graft active site, and specifically, it must have a carbon-carbon double bond in the rubber molecule. preferable.

There are no particular restrictions on the method of polymerizing the monomers, including emulsion polymerization,
Known techniques such as solution polymerization can be used.

In addition, the rubber component of component (4) does not need to be of one type;
It may be a mixture of 92 or more rubber components that are separately polymerized.

The monomers constituting the resin component of the rubber-containing styrenic resin, which is the component (4) in the present invention, include styrene, α
- Styrenic monomers such as methylstyrene, vinyltoluene, and t-butylstyrene; nitrile monomers such as acrylonitrile and methacrylate triyfl; Acid ester monomers), N-methylmaleimide, N-ethermaleimide, N-propylmaleimide, N-'/chlorohequinlumaleimide, N-phenylmaleimide, N-tolylmaleimide, N-xylylmaleimide, etc. There are maleimide monomers, etc., which are used alone or in copolymerization, but it is essential to contain a styrene monomer.

The component (4) used in the present invention is composed of a rubber component and a resin component as described above, and a graft structure is present at the interface between the rubber component having a spherical structure and the resin component which is a continuous phase. is necessary.

It is known that such a structure can be achieved by a so-called graft polymerization method in which part or all of the monomers constituting the resin component are polymerized in the presence of a rubber component. can also be produced by known graft polymerization techniques.

(4) In order to adjust the content rate of the rubber component contained in the component (4), it is also possible to mix a separately polymerized resin component with the component (4), but the separately polymerized resin component may be graft polymerized. It does not need to have the same composition as the resin component obtained in . For example, component (4) obtained by graft polymerizing acrylonitrile, styrene and methyl methacrylate in the presence of polybutadiene contains acrylonitrile, styrene and α
- It is possible to copolymerize methylstyrene and mix the resin fractions obtained.

Specific examples of component (A) of the present invention include high-impact polystyrene, ABS (acrylonitrile loop mediene-styrene) resin, heat-resistant AB8 (7-IJ lonitrile-butadiene-sterene-α-methylstyrene) resin,
hhs (acrylonitrile-acrylic acid ester-styrene) resin, Ar1 (acrylonitrile-EIPDM)
-Styrene] resin, MBAS (methyl methacrylate)
Examples include phtadiene-acrylonitrile-styrene) resin.

Next, in the method for producing the copolymer which is component (B) of the present invention, examples of fatty acid vinyl ester monomers used as raw materials include vinyl formate, vinyl acetate, vinyl propanoate, vinyl butanoate, and pentanoate. Vinyl, vinyl hexanoate, vinyl heptanoate, vinyl octoate, vinyl nonanoate, vinyl decanoate, vinyl dodecanoate, vinyl tetradecanoate, vinyl hexadecayate, vinyl octadecanoate, and the like.

On the other hand, examples of other copolymerizable monomers include olefin monomers such as ethylene, phlopylene, 1-butene, 2-butene, isobutylene, fuculobentene, nclohexene, norbornene, styrene, α-methylstyrene, t-
Butylstyrene, p-/tylstyrene nato styrenic monomers, methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, 7-chlorohexyl acrylate, octyl acrylate, hydroxyethyl acrylate, methoxyethyl acrylate, phenyl acrylate, glycidyl Acrylic acid ester monomers such as acrylate, methacrylic acid ester monomers such as methyl methacrylate, butyl methacrylate, glycidyl methacrylate, nitrile monomers such as acrylonitrile, methacrylaterile, methyl vinyl ether, ethyl vinyl ether, phthyl vinyl ether,
vinyl ether monomers such as phenyl vinyl ether,
Examples include non-logenated olefin monomers such as vinyl chloride and vinylidene chloride.

Examples of the long chain bifunctional monomer represented by the general formula 1 include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, pentaethylene glycol diacrylate, and nonaethylene glycol diacrylate. , polyethylene glycol diacrylate-based long-chain bifunctional monomers such as tetradecaethylene glycol diacrylate and eicosaethylene glycol diacrylate,
Polyethylene glycol dimethacrylate series such as diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, pentaethylene glycol dimethacrylate, nonaethylene glycol dimethacrylate, tetrazocanitereph glycol dimethacrylate, eicosaethylene glycol dimethacrylate Chain difunctional monomers, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tetrapropylene glycol diacrylate, pentapropylene glycol diacrylate, nonapropylene glycol diacrylate, tetradecapropylene glycol diacrylate, eicosapropylene glycol diacrylate Polypropylene glycol diacrylate long chain bifunctional monomers such as acrylates, dipropylene glycol dimethacrylate, tripropylene glycol dimethacrylate, tetrapropylene glycol dimethacrylate, pentapropylene glycol dimethacrylate, nonapropylene glycol dimethacrylate, tetradecapropylene Polypropylene glycol dimethacrylate long chain bifunctional monomers such as glycol dimethacrylate and eicosapropylene glycol dimethacrylate; mixed ester long chain bifunctional monomers such as polyethylene glycol monoacrylate monomethacrylate and polypropylene glycol monoacrylate monomethacrylate; Examples include quantitative substances.

These long chain bifunctional monomers may be used alone or in combination of two or more.

However, when producing the long-chain bifunctional monomer industrially, it is difficult to strictly limit the molecular weight distribution of polyethylene glycol or polypropylene glycol as raw materials; May include nonaethylene glycol diacrylate, octapropylene glycol dimethacrylate, decapropylene glycol dimethacrylate, and the like. Therefore, although it is industrially difficult to strictly limit the number of n in general formula I to one, this fact does not impede the effects of the present invention.

The amount of the long-chain difunctional monomer used is preferably α01 to 10 parts by weight, and cLO1 to 7Xi parts, based on 100 parts by weight of the monomers to be copolymerized as described above. However,
If this amount is less than 0.01 parts by weight, the effect of improving laminar peelability will be poor, while if it exceeds 10 parts by weight, the effect will be saturated.

Moreover, in addition to the long-chain bifunctional monomer, other polyfunctional vinyl monomers may be copolymerized with the component (B) in the present invention. Examples of polyfunctional vinyl monomers that can be used include divinylbenzene, ethylene glycol methacrylate), 1. ! S-butylene glycol dimethacrylate), 1,4-butylene glycol dimethacrylate, propylene glycol dimethacrylate, triallyl cyanurate, triallyl incyanurate, trimethylolpropane trimethacrylate, allyl acrylate, allyl methacrylate, vinyl acrylate, vinyl methacrylate, etc. Can be mentioned.

Component (B) of the present invention has a 4 to 9.8 (aaj/e
n)" solubility parameter,
A more preferable numerical range is &6 to 9.6 (ca4/lC
)"4.The solubility parameter referred to herein is a
Published in 1975, Brand Wrap (J.

13randrup) and Inmargut (IC
Using the solubility parameter value described in Polymer Band'book, 2nd edition, page N-557-4-559, the solubility parameter δT of the copolymer was calculated as follows: It is calculated by the following formula n from the solubility value (rameter δ) of the homopolymer of each vinyl monomer constituting the copolymer consisting of the monomers and its weight fraction Wn.

δT=ianWn/! Wn〔(Cat/cCPort...〔
u]fi-1fL"1 For example, let the solubility parameters of butyl polyacrylate and ethyl polyacrylate be &8 (aatA
x, 迦, 9. a (catAr, solubility of a copolymer consisting of 70 parts by weight of butyl polyacrylate and 30 parts by weight of polyethyl acrylate)
90 (catAr,)''.

If the solubility parameter of component (B) is less than a4 or more than 98, the environmental stress cracking resistance of the resin composition of the present invention will be low, which is not preferable.

Component (B) of the present invention must have a glass transition temperature of 20°C or lower, preferably 10°C or lower. When the glass transition temperature exceeds 20°C, the environmental stress cracking resistance of the resin composition of the present invention decreases, which is not preferable.

Furthermore, component (B) of the present invention has a gel content of 70% by weight.
It is necessary that the following is true. The gel content as used herein means that the component (B) is 1. Weigh it accurately and put it in a basket made of stainless steel wire mesh, weighing 400 mts and 7 mts.
g of toluene, left at 5°C for 24 hours, then pulled up and fixed, and then calculated according to the following formula (2).

[(B component insoluble matter weight)/1]×100(4)...
- [llI] If the gel content of component (B) exceeds 70% by weight, the environmental stress cracking resistance of the resin composition of the present invention will be low, which is not preferable.

There are no particular restrictions on the polymerization method for component (B) of the present invention, but production by emulsion polymerization is industrially most advantageous, and any known technique relating to emulsion polymerization can be applied.

In the present invention, 100 parts by weight of component (4) and 1 to 1 part of component (B)
50 parts by weight, preferably 2 to 40 parts by weight, but if the content of component (B) is less than 1 part by weight, the effect of improving environmental stress cracking resistance is insufficient, and if it exceeds 50 parts by weight, The effect is not saturated, and the rigidity is greatly reduced, which is undesirable.

In order to mix component (4) and (B) Jff1 minute in the present invention, a known mixing technique is applied to blend both components in an emulsified state, a particle state, or a molten state, and then melt-knead them. Well, you can easily get the desired mixture. When the component (B) is produced by an emulsion polymerization method,
The polymer latex can be blended with component (4) in an emulsified state, particulate state, or molten state, and melt-kneaded through a dehydration step or simultaneously with the dehydration step. Examples of melt-kneading equipment include panburi mixers, intensive mixers, mixtruders, co-kneaders, extruders, rolls, and the like. Also, JP-A-56-13165
The manufacturing method disclosed in Publication No. 6 can also be applied.

Furthermore, in the present invention, it is also possible to add additives other than those mentioned above, such as pigments, dyes, stabilizers, dispersants, reinforcing materials, fillers, lubricants, etc. The present invention is not limited to these Examples, although more specific explanations will be provided based on Examples and Reference Examples.

In addition, all parts and sections described in each example are based on weight.

Reference Example 1 (A) Preparation of Component (1) A-1, A-2, A-3, A-5 In the presence of the nine rubber latexes shown in Table 1, the corresponding monomers were added,
Manufactured by emulsion polymerization method.

(2) A-4 The monomers shown in Table 1 were added to a toluene solution of IPDM rubber to produce it by solution polymerization.

(3) A-6, A-7, A-8 It was produced by the monomer emulsion polymerization method shown in Section 1.

Reference Example 2 Preparation of component (B) 100 parts of pure water, 4 parts of partially saponified polyvinyl alcohol-A, 11 parts of potassium persulfate, and 2 parts of sodium acetate were added to a pressure autoclave.

After the contents were sufficiently replaced with nitrogen, f! Do not press-fit the entire amount of ethylene. 6011 contents
After raising the temperature to 100 ml, the entire amount of the monomers having the compositions shown in Table 2 except for ethylene was continuously added over 10 hours. The total amount of the initially injected ethylene and the continuously added monomers excluding ethylene was 100 parts.

After the addition was completed, the mixture was further stirred at 70° C. for 5 hours to complete the polymerization.

Table 3 shows the properties of the obtained component (B).

The abbreviations of the long chain bifunctional monomers used in Table 2 are as follows: 9PG: nonapropylene glycol dimethacrylate 3G; triethylene glycol dimethacrylate 4G; tetraethylene glycol dimethacrylate 9G: nonaethylene Glycol dimethacrylate 14G: Tetradecaethylene glycol dimethacrylate 23G:) Lieicosaethylene glycol dimethacrylate 9PAG: Nonapropylene glycol diacrylate 3 A G:) Lyethylene glycol diacrylate 9M G: Nonaethylene glycol diacrylate 1A A G: Tetra The physical property values of decaethylene glycol diacrylate were determined by the following method.

(1) Glass transition temperature CB) The solid obtained by pouring the component latex into an aqueous calcium chloride solution was dried and measured using a DuPont measuring instrument 910.
It was measured using a differential scanning calorimeter and a 990 thermal analyzer.

(2) Solubility parameter value of each polymer used to calculate the solubility parameter on each side of the vine freshness parameter [unit: (cat/eC)]
] is as follows.

Polybutyl acrylate: &8 Polyethylene: al Polyvinyl acetate: 9.4 Polyvinyl dodecanoate: a8 Polyacrylonitrile: 12.5 (3) Gel content (B) obtained by pouring component latex into an aqueous calcium chloride solution The solids were dried. The 1.02 minute amount was accurately weighed, processed as described above, measured, and calculated in 2).

Example 1 and Comparative Example 1 Table 1 (A-1) 80 parts of latex (as polymer) and Table 2CB) 20 parts of component latex (as polymer)
were mixed in a latex state, an aqueous calcium chloride solution was added thereto, the mixture was stirred at 95° C. after death, and the resulting prayer material was filtered to recover the polymer. After drying the resulting mixture, 40 parts of the mixture was mixed with 60 parts of Table 1 (A-6) powder, 4.
4'-isopropylidene-bis[monophenyl-dialkyl (C~0tsJ phosphite]) [manufactured by Adeka Argus Chemical Co., Ltd., MARK 1500]
] (hereinafter abbreviated as stabilizer) was mixed with α3 part in a Hennel mixer, and mixed with VC-4O manufactured by Chuo Kikai Seisakusho Co., Ltd.
(vented single-screw extruder) to obtain pellets.

Moldings were made using the obtained pellets and their physical properties were evaluated, and the results are shown in Table 4 Experiment Nos. 1 to 25.

Note that the measured values of the physical properties on the valley side were determined by the following method.

(1) Tensile υ yield point... ASTM D-61 (
2) Izot impact strength・・・ASTM D
-256 (3) Chemical resistance (environmental stress resistance requirements) ASTM D-658 Type 1 A dumbbell is given a deflection of 50 m and fixed to a jig, and ethylene glycol monoethyl ether is applied to m cloth L and left at a temperature of 23°C. Expresses the time in minutes until failure occurs. In the table>500 is 300
Indicates that it does not break after 3 minutes.

(4) Layered Peelability A 50×20×2 MO plate-like molded product having a 5×3×1 square gate was molded using a 5-ounce injection molding machine. In applied example 2 and reference example 2 (experiment numbers 26 to 32) described later, the resin temperature was 240°C, and in applied example 1 and reference example 1, the resin temperature was 200°C, and the injection speed was 90 wm / 81 ile.
s Mold temperature was set at 40°C.

The delamination property of the gate portion of the molded product was evaluated as follows in comparison with a standard sample.

AB indicates that it is located between A rank and B rank.

A: Not peeled off at all B; Slightly peeled O; Slightly peeled D: Significantly peeled off Numbers 1 to 19 are examples, and numbers 20 to 25 are comparative examples. As is clear from the comparative examples, when the glass transition temperature, gel content, and solubility parameters of component CB) deviate from the range of the present invention, the environmental stress resistance deteriorates, and the long-chain difunctional monomer deteriorates. If the amount used is insufficient, the occurrence of delamination phenomenon will be observed.

Example 2 and Comparative Example 2 In Example 1, Table 2 (B-3) was used as the (B) component,
Pellets were prepared in the same manner as in Example 1, except that the mixing ratio of (A-1) and (B-5) and the blending ratio of (A-6) powder were changed to those shown in Table 5. Obtained. A molded product was prepared from the obtained pellets and the physical properties were evaluated, and the results are shown in Table 5.

As is clear from Table 5, if the amount of component (B) added is insufficient, the environmental stress resistance requirements will be poor, and if it is too much, the rigidity will be poor and it will not be practical.

Example 3 and Comparative Example 3 pl (p, -1) latex and (B) component latex were mixed in a latex state with Table 1 (A-7) latex or (A-8) latex, and a calcium chloride aqueous solution was added. After the addition, the solution was stirred at 105-120°C. The obtained precipitate was filtered to recover the polymer, and after drying, α5 parts of the stabilizer used in Example 1 was added to 100 parts of the mixture, and VO-4 manufactured by Chuo Kikai Seisakusho Co., Ltd.
0 to obtain pellets.

A molded article was made using the obtained pellet and its physical properties were evaluated, and the results are shown in Table 6.

As is clear from Table 6, when (A-7) or (A-8) is used as the matrix resin, the resin has a high melt viscosity and is subjected to high shear stress during injection molding. When a component (CB) that does not copolymerize with a functional monomer is used, a remarkable layer delamination phenomenon is observed (Table 6 Experiment Nos. 41 to 4).
3).

However, with component (E) of the present invention, little or no peeling phenomenon was observed, demonstrating the effects of the present invention (Experiment Nos. 55 to 40 in Table 6).

Example 4 and Comparative Example 4 Table 1 (A) component powder was mixed with Table 2 (B-3) 8 parts of latex (
After mixing with 1.3 parts of stabilizer in a Henschel mixer, TKM-50 manufactured by Toshiba Machine Co., Ltd.
(a co-rotating twin-screw kneading extruder) to obtain pellets.

The obtained pellets were molded into υ molded articles and their physical properties were evaluated, and the results are shown in Table 7.

It can be seen that the effects of the present invention are exhibited regardless of the type of rubber of component (A).

[Effect of the invention] As explained above, the thermoplastic resin composition of the present invention has the following effects:
The molded product exhibits remarkable effects in that the layered peeling phenomenon is difficult to occur and it exhibits excellent effects in terms of environmental stress resistance requirements.

Claims (1)

[Scope of Claims] 1. Including (A) a rubber-containing styrenic resin and (B) a copolymer, the (B) based on 100 parts by weight of the component (A)
In a thermoplastic resin composition containing 1 to 50 parts by weight of the component, the copolymer of component (B) is a fatty acid vinyl ester monomer, or a fatty acid vinyl ester monomer and another copolymerizable monomer. The following general formula is added to 100 parts by weight of the mixture with
I: ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] [In the formula, R^1 and R^2 are H or CH_3 groups, and X is -(
CH_2-CHR^3-O)-_n_-_1CH_2-
CHR^3- group (n is an integer of 2 or more, R^3 is the same or different, and is H or CH_3 group)] 0.01 to 10 long-chain bifunctional monomers The solubility parameter obtained by copolymerizing parts by weight is 8.4 to 9.
8 (cal/cc)^1^/^2, a glass transition temperature of 20°C or less, and a gel content of 70% by weight or less. .