JPH0768406B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a thermoplastic resin composition. More specifically, a resin composition containing a polyfunctional monomer and a specific phenolic compound in a thermoplastic resin to suppress gel formation to obtain a molded article having a smooth surface, and a polyfunctional monomer in the thermoplastic resin , A specific thiophosphite, and a specific phenolic compound are blended to obtain a resin composition which is excellent in metal deterioration resistance and suppresses gel generation to obtain a molded product having a smooth surface.

[Conventional technology]

Thermoplastic resins have excellent heat resistance, rigidity, tensile strength, and chemical resistance, and are used in many applications. However, the temperature dependence of the melt viscosity is large, and when heated above the melting point, the viscosity drops sharply, the gas retention during foaming is poor, and the shape retention when the film is heated is insufficient. It has some drawbacks. As a means for improving this, by molding a composition obtained by blending a polyfunctional monomer with a thermoplastic polymer, and irradiating the resulting molded article, for example, a film with an electron beam or γ rays, the rigidity is increased,
Although it has been attempted to obtain a molded product having high mechanical strength, it was difficult to obtain a molded product having a flat and smooth surface due to an early crosslinking reaction during molding. Further, thermoplastic resins, synthetic rubbers, hydrocarbon oils, etc. are heavy metals such as copper, iron, cobalt, manganese, vanadium and other metals, alloys, oxides,
It is well known that when it contains a salt or the like or comes into contact with the heavy metals, it is significantly decomposed and deteriorated.

Therefore, various heavy metal deactivators have been added. In particular, among thermoplastic resins, polyolefin resins, particularly polypropylene resins, deteriorate in a few months of contact with heavy metals such as copper and their mechanical strength decreases, making them practically unusable. When coloring is performed, a pigment containing a heavy metal is used as the colorant to be used. This effectively limits the colorants that can be used.

For this reason, chelating agents such as oxalic acid derivatives, epoxy condensates, hydrazide derivatives, salicylic acid derivatives, and triazine derivatives are used as heavy metal deactivators.

[Problems to be solved by the invention]

However, when a composition obtained by blending a thermoplastic resin with a polyfunctional monomer is melt-kneaded when granulating or molding using the composition, the polyfunctional monomer and the thermoplastic resin are melted and kneaded by the applied heat or shearing force. A cross-linking reaction occurs with the resin,
There are problems that the viscosity is increased at the time of the melt-kneading, a speckled striped pattern is generated on the surface of the obtained molded product, and the smoothness of the surface of the molded product is lost to deteriorate the appearance. ing.

Further, the conventional heavy metal deactivators generally have many chelating agents that are poorly compatible with the thermoplastic resin, and thus have poor dispersibility in the thermoplastic resin, causing phenomena such as bloom and sublimation, and resulting in product quality. Is a cause of problems such as deterioration of the appearance, contamination of the die and mold of the molding machine, and deterioration of appearance due to blooming on the surface of the molded product. Further, unless the epoxy condensate is used in a large amount, it is not effective in preventing deterioration of heavy metals, and when a composition containing such an epoxy condensate is heated, it causes discoloration, which is a problem.

The resin composition in which the polyfunctional monomer and the above-mentioned heavy metal deactivator are mixed with the thermoplastic resin is a blooming of a molded article by using a heavy metal deactivator by selecting a chelating agent having good compatibility. Although the adverse effects such as mold contamination are prevented to some extent and the resistance to heavy metal deterioration is improved, the crosslinking reaction between the polyfunctional monomer and the thermoplastic resin that occurs when the heat or shearing force applied during melt kneading or molding is large ( (Hereinafter referred to as early cross-linking reaction), which causes an increase in viscosity at the time of melt-kneading or causes a spotted striped pattern on the surface of the molded product, resulting in deterioration of appearance of the molded product. The loss of smoothness of the surface and the surface has not been solved yet.

An object of the present invention is to provide a thermoplastic resin composition which prevents a premature crosslinking reaction to give a molded article having excellent appearance, and further prevents a premature crosslinking reaction, and a thermoplastic resin composition which is excellent in heavy metal deterioration resistance. It is an attempt to provide something.

[Means for solving problems]

The present inventors have earnestly studied about the above-mentioned problems relating to the thermoplastic resin composition, that is, prevention of an early crosslinking reaction at the time of granulation or molding and prevention of an early crosslinking reaction, and improving heavy metal deterioration. went.

As a result, when a thermoplastic resin is blended with a polyfunctional monomer and a specific amount of a specific phenolic compound, an early crosslinking reaction is prevented, a molded article having excellent appearance is provided, and the thermoplastic resin composition contains a large amount. The present invention has been completed by discovering that when a specific amount of a functional monomer, a specific phenolic compound, and a specific thiophosphite is blended, a premature crosslinking reaction is prevented and a molded product excellent in heavy metal deterioration resistance is also provided. .

The present invention is a thermoplastic resin composition prepared by mixing 0.05 to 10 parts by weight of a polyfunctional monomer and 0.01 to 3 parts by weight of a phenolic compound represented by the following general formula [I] with 100 parts by weight of a thermoplastic resin. is there.

(However, R ₁ represents hydrogen or a methyl group, and R ₂ and R ₃ each represent hydrogen or the same or different alkyl group having 1 to 8 carbon atoms.
same as below. ) In addition, as a resin composition which also imparts resistance to deterioration of heavy metals to 100 parts by weight of a thermoplastic resin, a polyfunctional monomer of 0.0
5 to 10 parts by weight, 0.01 to 3 parts by weight of the phenolic compound represented by the general formula [I], and one or more selected from the group of thiain phytes represented by the general formulas [II] to [V]. Is 0.01 to 3 parts by weight, and is a thermoplastic resin composition.

Examples of the thermoplastic resin to which the present invention is applied include polyolefin resin, polyvinyl chloride, polyvinylidene chloride, and vinyl chloride-vinylidene chloride copolymer. In particular, polyolefin resin such as polyethylene, propylene homopolymer, propylene and ethylene containing propylene as a main component, butene-1, pentene-1, hexene-1,
4-methylpentene-1, heptane-1, octene-
1, it is preferable to use a crystalline copolymer with one or more selected from decene-1, poly-4-methylpentene-1, ethylene-propylene rubber and a mixture of two or more thereof. .

As the polyfunctional monomer, triallyl cyanurate,
Triallyl isocyanurate, acrylic acid ester, methacrylic acid ester, for example, ethylene glycol diacrylate, ethylene glycol dimethacrylate,
Diethylene glycol diacrylate, diethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, etc., and also divinylbenzene, diarylphthalate, quinonedioxime, benzoquinonedioxime, Examples thereof include N, N'-m-phenylene bismaleimide, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane.

Acrylic acid ester as a suitable polyfunctional monomer,
Especially trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, or two of these. The above mixture can be mentioned.

As the phenolic compound represented by the general formula [I], 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2-t-butyl-6 -(3-t-butyl-2-
Hydroxy-5-ethylbenzyl) -4-ethylphenyl acrylate, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-s-butylbenzyl) -4-
s-Butylphenyl acrylate, 2-t-butyl-6
-(3,5-di-t-butyl-2-hydroxybenzyl)
-4-t-butylphenyl acrylate, 2-t-octyl-6- (3-t-octyl-2-hydroxy-5-
Methylbenzyl) -4-methylphenyl acrylate,
2-t-butyl-6- [3-t-butyl-2-hydroxy-5-s-butyl (α-methylbenzyl)]-4-s
-Butylphenyl acrylate, 2-t-butyl-6-
Examples include [3,5-di-t-butyl-2-hydroxy (α-methylbenzyl)]-4-t-butylphenyl acrylate. Especially 2-t-butyl-6-
(3-t-Butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate is preferred.

The amount of the phenolic compound added is 0.01 to 3 parts by weight with respect to 100 parts by weight of the thermoplastic resin. If the amount added is less than 0.01 parts by weight, the effect of preventing an early crosslinking reaction that occurs when the heat or shearing force applied during melt-kneading or molding is large is not sufficient. It is acceptable to add 3 parts by weight or more, but the effect is saturated and it is wasted.

Examples of the thiophosphite include trilauryltrithiophosphite, tridecyltrithiophosphite, tribenzyltrithiophosphite, tricyclohexyltrithiophosphite, tri (2-ethylhexyl) trithiophosphite, trinaphthyltrithiophosphite, diphenyldecyltrithiophosphite. Fight, diphenyllauryl trithiophosphite,
Tetralauryl-4-oxaheptylene-1,7-tetrathiophosphite, tetrakis (mercaptolauryl) -1,6-dimercapto-hexylene-diphosphite, pentakis (mercaptolauryl) bis (1,6-
Hexylene-dimercapto) -trithiophosphite, tetrakis (mercaptolauryl) -2,9-dimercapto-para-methylene-diphosphite, bis (mercaptolauryl) -1,6-dimercaptohexylene-
Examples thereof include bis (benzene) phosphonite, dioctyldithiopentaerythritol diphosphite, dilauryldithiopentaerythritol diphosphite, and phenyllauryldithiopentaerythritol diphosphite. Trilauryl trithiophosphite can be preferably used. The amount of the thiophosphite compounded is 100 parts by weight of the thermoplastic resin,
It is 0.01 to 3 parts by weight, more preferably 0.05 to 2 parts by weight, and particularly preferably 0.1 to 2 parts by weight.

When the content is less than 0.01 parts by weight, the effect of improving the deterioration of heavy metals is poor, and when it exceeds 3 parts by weight, the effect of improving the deterioration of heavy metals is saturated, and no further improvement is observed, which is not preferable.

The compounding amount of the polyfunctional monomer is 0.05 to 10 parts by weight, and more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the thermoplastic resin.

If the blending amount is less than 0.05 parts by weight, the effect of improving the deterioration of heavy metals cannot be obtained, and if it exceeds 10 parts by weight, the improving effect is saturated, and no further improvement in the effect is observed, but rather improvement is achieved. This is not preferable because the effect will decrease.

In the thermoplastic resin composition of the present invention, if necessary, various additives such as phenol-based, thioether-based, phosphorus-based antioxidants, heat deterioration inhibitors, light stabilizers, clarifiers,
Nucleating agents, lubricants, antistatic agents, antifog agents, antiblocking agents, pigments, radical generators, neutralizing agents or dispersing agents for metallic soaps, inorganic fillers (talc, mica, clay, wollastonite, zeolite) , Calcium silicate, glass fiber, carbon fiber, etc., organic fillers (wood flour, pulp,
Waste paper, synthetic fibers, natural fibers, etc.), flame retardants, etc. can be used together within the range not impairing the object of the present invention.

The method for producing the thermoplastic resin composition of the present invention includes, for example, a predetermined amount of a specific thiophosphite in a thermoplastic resin,
After mixing the (meth) acrylic acid ester and the specific phenolic compound with a usual mixing device, for example, Henschel mixer (trade name of Mitsui Miike Seisakusho), super mixer, ribbon blender, tumbler mixer, etc., roll, Banbury mixer, It can be obtained by melt-kneading at a melt-kneading temperature of 150 ° C. to 270 ° C. and pelletizing with a melt-kneading device such as an extruder.

〔Example〕

Specific examples of the present invention will be described with reference to Examples and Comparative Examples, but it goes without saying that the present invention is not limited thereto.

The evaluation methods used in Examples and Comparative Examples were as follows.

(1) Deterioration resistance to heavy metals A 25 mm long, 50 mm wide, 1 mm thick test piece molded by an injection molding method is fixed by closely adhering a 20 mm long, 30 mm wide, 0.3 mm thick copper plate with a well-polished surface. It is put in a circulating hot air oven at 150 ° C and the number of days until the test piece cracks and cracks is measured, and the quality of heavy metal deterioration resistance is evaluated.

(2) Evaluation of surface roughness Using an injection molding machine (M32J) manufactured by Meiki Seisakusho, a resin temperature of 25
0 ℃, mold temperature 50 ℃, residence time in the cylinder is 0
Minutes, 5 minutes, 10 minutes, 20 minutes, 30 minutes, then injection
A flat plate having a length of 50 mm, a width of 50 mm and a thickness of 2 mm was formed.

The flatness of the surface of this flat plate was visually evaluated, and one that was completely smooth was evaluated as ○, and one that caused surface roughness due to gel was evaluated as ×.
It was determined.

(3) Measurement of gel fraction After retaining in a cylinder of an injection molding machine at 250 ° C for 30 minutes, the obtained molded product is hot pressed to have a wall thickness of 150 µm.
It was made into a film and cut into small pieces with scissors. 150 this
A certain amount was weighed on a cylindrical filter paper made of a mesh wire mesh, and extracted with a Soxhlet extractor for 8 hours using xylene as a solvent. The remaining portion in the cylindrical filter paper was vacuum dried for one day and then weighed to obtain a gel component.

Example 1 As a thermoplastic resin, a melt flow rate (a discharge amount of the molten resin for 10 minutes when a load of 2.16 Kg at a temperature of 230 ° C. was added for 10 minutes) 8.5 g / 10 minutes and an ethylene propylene block copolymerization weight of ethylene content 8.5% by weight 100 parts by weight of the combined product, 0.15 parts by weight of 2,6-di-t-butyl-para-cresol as an antioxidant, Irganox 1010 (trade name of Ciba Geigy) 0.05
Parts by weight, 0.1 parts by weight of calcium stearate as a neutralizing agent, 3 parts by weight of trimethylolpropane triacrylate as a polyfunctional monomer, and 2-t-butyl-6- (3-t- as a phenolic compound. Butyl-
2-Hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (0.3 parts by weight) was blended as shown in Appendix 1 and stirred for 3 minutes with a Henschel mixer, and the resulting mixture was biaxial with a diameter of 45 mm. It was melt-kneaded at 200 ° C. using an extruder and extruded into pellets.

Using the obtained pellets, a test piece was prepared by an injection molding method and used for the test.

Examples 2 to 5 The same ethylene-propylene block copolymer as in Example 1 was adopted as a polyolefin resin, and the same polyfunctional monomer and phenolic compound as in Example 1 were used, and trilauryltrithiophosphite was used as thiophosphite. 0.5 part by weight was compounded as shown in Table 1 and Example 1 was added.
It was subjected to the test according to.

Comparative Example 1 As the polyolefin resin, the same ethylene-propylene block copolymer as in Examples 1 to 5 was adopted, and only the same polyfunctional monomer as in Example 1 was blended, and the mixture was subjected to the test according to Example 1. did.

Example 6 As a thermoplastic resin, a resin obtained by blending 92 parts by weight of the ethylene-propylene block copolymer used in Example 1 with 8 parts by weight of high-density polyethylene was adopted. The polyfunctional monomer, phenolic compound, and thiophosphite used in Examples 2 to 5 were added thereto as shown in Table 1, and 22 parts by weight of decabromodiphenyl ether and 8 parts by weight of antimony trioxide were used as a flame retardant. Was blended and subjected to the test according to Example 1.

Comparative Example 2 The same thermoplastic resin as in Example 6 was added with thiophosphite,
The same polyfunctional monomer and flame retardant were blended in the same parts by weight, and the case where only the phenolic compound was not blended was subjected to the test according to Example 1.

Example 7 A test was conducted according to Example 1 except that pentaerythritol tetraacrylate was used as the polyfunctional monomer used in Example 1 and the addition amount of thiophosphite was changed to the addition amount shown in Table 1. .

Comparative Example 3 According to Example 1, except that pentaerythritol tetraacrylate was used as the polyfunctional monomer used in Example 1 and the addition amounts of thiophosphite and the phenolic compound were changed to the addition amounts shown in Appendix 1. It was submitted to the test.

As is clear from Appendix 1, the molded articles obtained in the examples using the composition of the present invention have a rough surface on the molded article in Comparative Example 1 at a residence time of 250 ° C. for 5 minutes. Examples 2 to 5 in which a phenolic compound and thiophosphite were added
The surface of the molded product was smooth even after dwelling for 5, 10, 20 and 30 minutes, respectively, which correlates with the compounding amount of the phenolic compound, which is clearly considered to be the effect of compounding the phenolic compound. To be

Even in Example 1 in which thiophosphite was not mixed, the surface of the molded article was smooth even after 20 minutes of residence, as in Example 4.

Regarding the gel fraction of what was retained at 250 ° C for 30 minutes,
Compared with 35.0% by weight of Comparative Example 1 in which the phenolic compound and thiophosphite were not blended, in Example, it decreased to 31.5 to 18.0% by weight depending on the added amount of the phenolic compound.

Also, in Example 6 and Comparative Example 2 in which a flame retardant was added as a kind of filler, a remarkable difference was observed in the surface roughness and the gel fraction.

As for the resistance to deterioration of heavy metals, Example 1 containing no thiophosphite and Comparative Example 1 had no 2 days, while Example 2 containing 0.5 part by weight of thiophosphite,
In 3,4,5,6,7 and Comparative Examples 2 and 3, heavy metal deterioration resistance was exhibited for 15 days or more.

In addition, from Example 7 and Comparative Example 3, even when pentaerythritol tetraacrylate is used as the polyfunctional monomer, the improvement effect on the surface of the molded product by adding the phenol compound is confirmed.

〔The invention's effect〕

The thermoplastic resin composition of the present invention contains a specific phenolic compound, as compared with a resin composition containing only a polyfunctional monomer, to obtain a molded product having a smooth surface with suppressed gel generation. I was able to. Furthermore, by blending a specific thiophosphite for imparting heavy metal deterioration resistance, and by further blending a specific phenolic compound, gel generation was suppressed while imparting heavy metal deterioration resistance, and the surface was smooth. A molded product could be obtained.

This makes it possible to suitably use a thermoplastic resin, particularly a polyolefin resin, for automobile parts, home electric appliance parts, and OA equipment parts.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C08L 27/08 LFU 101/00

Claims (8)

[Claims] 1. To 100 parts by weight of a thermoplastic resin, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol. Diacrylate, diethylene glycol dimethacrylate, trimethylol ethylene triacrylate, trimethylol ethylene trimethacrylate, pentaerythritol tetraacrylate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene,
Diaryl phthalate, quinone dioxime, N, N'-m
A heat obtained by blending 0.05 to 10 parts by weight of a polyfunctional monomer consisting of any one of phenylene bismaleimide or a mixture of two or more thereof and 0.01 to 3 parts by weight of a phenolic compound represented by the following general formula [I]. Plastic resin composition. (However, R ₁ represents hydrogen or a methyl group, and R ₂ and R ₃ each represent hydrogen or the same or different alkyl group having 1 to 8 carbon atoms.
same as below. ) 2. The thermoplastic resin according to claim 1, wherein the thermoplastic resin is a polyolefin resin, polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinylidene chloride copolymer or a mixture of two or more of these resins. Composition. 3. A polyolefin resin comprising a propylene homopolymer, propylene as a main component, ethylene, butene-1,
Pentene-1, hexene-1, 4 methylpentene-1,
Crystalline copolymer with one or more selected from the group of heptene-1, octene-1, and decene-1, polyethylene, poly-4-methylpentene-1, ethylene-propylene rubber, or one of these. The thermoplastic resin composition according to claim 2, which is a mixture of two or more kinds. 4. A phenolic compound is 2-t-butyl-6.
The thermoplastic resin composition according to any one of claims 1 to 3, which is-(3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate. 5. To 100 parts by weight of the thermoplastic resin, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol. Diacrylate, diethylene glycol dimethacrylate, trimethylol ethylene triacrylate, trimethylol ethylene trimethacrylate, pentaerythritol tetraacrylate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene,
Diaryl phthalate, quinone dioxime, N, N'-m
-0.05 to 10 parts by weight of a polyfunctional monomer consisting of one kind or a mixture of two or more kinds of phenylene bismaleimide, 0.01 to 3 parts by weight of a phenolic compound represented by the following general formula [I] and the following general formula [II] to 0.01 to 3 of one or more selected from the group of thiophosphites represented by [V]
A thermoplastic resin composition containing 1 part by weight. (Wherein R ₄ represents a number 6-20 alkyl group, a cycloalkyl group or an aryl group having a carbon, R ₅ is -SR ₅ or -R _5, R ₆ is -SR ₆ or -R ₆
Wherein -R ₅ and -R ₆ represent the same or different alkyl group having 6 to 20 carbon atoms, cycloalkyl group or aryl group. X is _{- (CH 2) l n-,} - (CH 2) n-O- (CH 2) m- or And n, m, and l represent the same or different integers of 2 to 6. same as below. ) 6. The thermoplastic resin according to claim 5, wherein the thermoplastic resin is a polyolefin resin, polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinylidene chloride copolymer or a mixture of two or more of these resins. Composition. 7. A polyolefin resin comprising a propylene homopolymer, propylene as a main component, ethylene, butene-1,
Pentene-1, hexene-1, 4 methylpentene-1,
Crystalline copolymer with one or more selected from the group of heptene-1, octene-1, and decene-1, polyethylene, poly-4-methylpentene-1, ethylene-propylene rubber, or one of these. The thermoplastic resin composition according to claim 6, which is a mixture of two or more of 8. A phenolic compound is 2-t-butyl-6.
The thermoplastic resin composition according to any one of claims 5 to 7, which is-(3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate.