JP3519504B2 - Composite rubber-based graft copolymer, method for producing powder thereof, and thermoplastic resin composition thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite rubber-based graft copolymer having improved coagulability, a method for producing a powder thereof, and a thermoplastic resin composition thereof.

[0002]

Various resins such as vinyl chloride resin, acrylonitrile-styrene copolymer resin, and polycarbonate resin are widely used, but their mechanical properties are not sufficient. It has been proposed to add various modifiers in order to improve the mechanical properties of these resins, especially the impact resistance.

For example, as a weather resistance and impact resistance modifier,
Various composite rubber-based graft copolymers have been proposed in which a vinyl-based monomer is graft-polymerized to a composite rubber including a polyorganosiloxane component and an alkyl (meth) acrylate rubber component (for example, JP-A-62-280210). No. 63-69859, Japanese Patent Laid-Open No. 1-2799.
54, etc.).

The composite rubber-based graft copolymer disclosed in the above publication, for example, the composite rubber described in Example 3 of JP-A-62-280210, which has a polyorganosiloxane content of about 42%. The composite rubber-based graft copolymer latex in which 40% by weight of a vinyl monomer such as methyl methacrylate is grafted has good coagulability, but since the composite rubber content is as low as 60% by weight, it coagulates. The impact resistance of the resulting composite rubber-based graft copolymer is not sufficient.

Further, a composite rubber-based graft copolymer obtained by grafting 13% by weight of styrene onto the composite rubber having a polyorganosiloxane content of 43% by weight described in Example 6 of JP-A-63-69859. Has a high composite rubber content of as high as 87% by weight, but is excellent in impact resistance development. However, when the composite rubber-based graft copolymer latex is coagulated, coarse particles tend to be generated, and there is a problem in coagulation. .

Further, a composite rubber having a polyorganosiloxane content of 5% by weight, which is described in Example 8 of JP-A-1-279954, contains 3 parts of methyl methacrylate.
The composite rubber-based graft copolymer latex obtained by grafting 0% by weight has good coagulability, but the composite rubber content is as low as 70% by weight. Therefore, the impact resistance of the composite rubber-based graft copolymer obtained by coagulation is low. The expression is not sufficient.

As described above, in the polyorganosiloxane composite rubber-based graft copolymer, a method of increasing the composite rubber content to exhibit high impact resistance is a problem in the coagulation property of the composite rubber-based graft copolymer latex. There was a point.

[0008]

Therefore, as a result of intensive studies by the present inventors, a specific amount of n-octane was obtained during the graft polymerization.
By using the chill mercaptan, while maintaining excellent impact resistance, it found that the resulting composite rubber-based graft copolymer having excellent coagulation properties, and have completed the present invention.

That is, the first gist of the present invention is that a vinyl-based monomer and the vinyl-based monomer are used in the presence of a composite rubber latex comprising a polyorganosiloxane component and a (meth) acrylic acid ester rubber component. Monomer 100
It is a composite rubber-based graft copolymer obtained by adding 0.1 to 5 parts by weight of n-octyl mercaptan to parts by weight and graft-polymerizing.

The second gist is that the vinyl-based monomer and the vinyl-based monomer 100 are added in the presence of a composite rubber latex containing a polyorganosiloxane component and a (meth) acrylic acid ester rubber component. 0 to parts by weight.
A method for producing a composite rubber-based graft copolymer powder, which comprises adding 1 to 5 parts by weight of n-octyl mercaptan to carry out graft polymerization and coagulating the obtained composite rubber-based graft copolymer latex. It is in.

Further, the third gist is that a polymer of one or more monomers selected from vinyl chloride resins, aromatic alkenyl compounds, methacrylic acid esters, acrylic acid esters and vinyl cyanide compounds, and polyphenylene. At least one heat selected from the group consisting of a mixture of ether and polystyrene, polyacetal resin, polyester resin, polycarbonate resin, polyamide resin, polyphenylene sulfide resin, ABS resin and (co) polymer of ethylenically unsaturated monomer. A thermoplastic resin composition comprising a plastic resin and the above composite rubber-based graft copolymer.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The polyorganosiloxane component in the present invention can be prepared by various methods, for example, by using an organosiloxane mixture containing a diorganosiloxane and, if desired, a polyorganosiloxane graft crosslinker or a polyorganosiloxane crosslinker. Polymerize by
It can be obtained as a polyorganosiloxane latex, but a method of emulsifying and polymerizing a raw material is preferable. For example, a method of adding an emulsifier, water, and dodecylbenzenesulfonic acid or sulfuric acid to the raw material, emulsifying the mixture using an emulsifying device such as a homomixer or a homogenizer, and leaving it for a predetermined time, and then neutralizing it with an alkaline substance, or the raw material A method in which an emulsifier and water are added and the mixture is emulsified by using an emulsifying device such as a homomixer or a homogenizer, dropped into a dodecylbenzenesulfonic acid aqueous solution at a constant rate, left standing for a predetermined time, and then neutralized with an alkaline substance is mentioned. To be

Examples of the diorganosiloxane used in the present invention include cyclic organosiloxanes having 3 or more membered rings, and those having 3 to 6 membered rings are preferably used. Specific examples of preferable cyclic organosiloxanes include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane and octaphenylcyclo. Tetrasiloxane etc. can be illustrated, and these are used individually or in mixture of 2 or more types. The amount of cyclic organosiloxane used is preferably 60% by weight or more, and more preferably 70% by weight or more in the polyorganosiloxane.

In the present invention, a crosslinking agent for polyorganosiloxane can be optionally used in forming the polyorganosiloxane. As the cross-linking agent for polyorganosiloxane, a trifunctional or tetrafunctional silane-based cross-linking agent, that is, a silane compound having three or four alkoxy groups is used, and specific examples thereof include trimethoxymethylsilane and triethoxyphenyl. Examples thereof include silane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, and tetrabutoxysilane. As the crosslinking agent for polyorganosiloxane, a tetrafunctional one is preferable, and tetraethoxysilane is particularly preferable among the tetrafunctional crosslinking agents. The amount of the crosslinking agent for polyorganosiloxane used is 0 to 30 in the polyorganosiloxane.
The content is preferably wt%, and more preferably 0 to 10 wt%. Even if the cross-linking agent for polyorganosiloxane is used in an amount exceeding 30% by weight, it does not contribute to the formation of a further cross-linked structure.

In the present invention, when forming the polyorganosiloxane component, a graft crossing agent for polyorganosiloxane can be further used. The graft crossing agent for polyorganosiloxane means that the alkoxysilane part thereof is involved in the polymerization and is incorporated into the polyorganosiloxane, but at this time, it does not react and the poly (organosiloxane) in the presence of the polyorganosiloxane for the subsequent preparation of the composite rubber is used. A silane compound having a functional group that reacts during polymerization of a (meth) acrylate rubber, and as a specific example thereof, the following formula (1-
The compound etc. which can form the unit represented by 1)-(1-4) are used.

CH ₂ = CR ² -COO- (CH ₂ ) _p -SiR ¹ _n O _{(3-n) / 2} (1-1) CH ₂ = CH-SiR ¹ _n O _{(3-n) / 2} ( ^{_{1-2) CH 2 = CR 2 -C}} 6 H 4 -SiR 1 n O (3-n) / 2 (1-3) HS- (CH 2) p -SiR 1 n O (3-n) / 2 (1-4) (In the above formula, R ¹ is a methyl group, an ethyl group, a propyl group or a phenyl group, R ² is a hydrogen atom or a methyl group, n is 0, 1 or 2, and p is 1 to 6. Indicates the number.)
Among these, (meth) acryloyloxysilane capable of forming the unit of the formula (1-1) has a high grafting efficiency and therefore can form an effective graft chain, which is advantageous in view of impact resistance expression. is there. Methacryloyloxysilane is particularly preferable as a unit capable of forming the unit of the formula (1-1).

Examples of the unit capable of forming the unit of the formula (1-2) include vinyltrimethoxysilane and vinylmethyldimethoxysilane, and 4-vinyl can form the unit of the formula (1-3). Phenyldimethoxymethylsilane, 4-vinylphenyltrimethoxysilane and the like can be exemplified, and as a unit capable of forming the unit of the formula (1-4), γ-
Examples thereof include mercaptopropyldimethoxymethylsilane, γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyldiethoxyethylsilane.

Specific examples of methacryloyloxysiloxane include β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropyltrimethoxysilane and γ-. Examples thereof include methacryloyloxypropyldiethoxymethylsilane, γ-methacryloyloxypropylethoxydiethylsilane, δ-methacryloyloxybutyldiethoxymethylsilane, and among these, γ-methacryloyloxypropyldimethoxymethylsilane and γ-methacryloyloxypropyltrisilane. Methoxysilane is more preferred. The amount of the graft crossing agent for polyorganosiloxane used is 0 to 10% by weight in the polyorganosiloxane, and
It is preferably about 5% by weight.

The emulsifier used in the emulsion polymerization is preferably an anionic emulsifier, and is an emulsifier selected from sodium alkylbenzenesulfonate, sodium laurylsulfonate, sodium sulfosuccinate, sodium polyoxyethylene nonylphenyl ether sulfate and the like. Is used. Particularly, sulfonic acid-based emulsifiers such as sodium alkylbenzene sulfonate and sodium lauryl sulfonate are preferable.

These emulsifiers are preferably used in the range of about 0.05 to 5 parts by weight based on 100 parts by weight of the organosiloxane mixture. When the amount used is small, the dispersion state becomes unstable, and it becomes impossible to maintain the emulsified state with a fine particle size. Further, if the amount used is large, the coloring caused by the polyorganosiloxane emulsifier becomes severe, which is inconvenient.

Number average particle size of the polyorganosiloxane latex in the present invention (measured by a quasi-elastic light scattering method)
Is not particularly limited, but is preferably in the range of 10 to 600 nm. If it is out of this range, the impact resistance of the composite rubber-based graft copolymer obtained tends to decrease.

To the polyorganosiloxane latex produced in this manner, a (meth) acrylate rubber component composed of an alkyl (meth) acrylate and a polyfunctional alkyl (meth) acrylate is added, and the poly (meth) acrylate is added. A composite rubber latex can be obtained by impregnating a polyorganosiloxane with an acrylate rubber component and then polymerizing it.

To the polyorganosiloxane latex,
When dipping and polymerizing the (meth) acrylic acid ester, the ratio of the (meth) acrylic acid ester rubber component consisting of polyorganosiloxane, alkyl (meth) acrylate and polyfunctional alkyl (meth) acrylate is Siloxane 0.1 to 99% by weight, (meth) acrylic acid ester rubber component 99.9 to 1% by weight are preferable, and further polyorganosiloxane 1 to 35% by weight, (meth) acrylic acid ester rubber 99 to 65% by weight.
Is.

Examples of the alkyl (meth) acrylate used in the present invention include methyl acrylate, ethyl acrylate, n-propyl acrylate,
Examples thereof include alkyl acrylates such as n-butyl acrylate and 2-ethylhexyl acrylate, and alkyl methacrylates such as hexyl methacrylate, 2-ethylhexyl methacrylate and n-lauryl methacrylate, and the use of n-butyl acrylate is particularly preferable.

As the polyfunctional alkyl (meth) acrylate, for example, allyl methacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate,
Examples thereof include triallyl cyanurate and triallyl isocyanurate.

The amount of the polyfunctional alkyl (meth) acrylate used is 0.1 in the (meth) acrylic acid ester component.
Is preferably 20 to 20% by weight, more preferably 0.5 to 1
It is 0% by weight.

The alkyl (meth) acrylate and polyfunctional alkyl (meth) acrylate may be used alone or in combination of two or more.

In order to produce a latex of a composite rubber, the above-mentioned (meth) acrylic acid ester component is added to the latex of the neutralized polyorganosiloxane component, and a usual radical polymerization initiator is allowed to act to polymerize. As the polymerization initiator, a peroxide, an azo initiator, or a redox initiator in which an oxidizing agent and a reducing agent are combined is used.
Among these, a redox type initiator is preferable, and a sulfoxylate type initiator in which ferrous sulfate, ethylenediaminetetraacetic acid disodium salt, Rongalite, and hydroperoxide are combined is particularly preferable.

A latex of a composite rubber is obtained in which the polyorganosiloxane component and the poly (meth) acrylic acid ester rubber component are substantially inseparable with the progress of polymerization.

In the practice of the present invention, a polyorganosiloxane rubber obtained by using octamethyltetracyclosiloxane as the dialkylorganosilane and γ-methacryloyloxypropyldimethoxymethylsilane as the siloxane-based graft crossing agent is used. It is preferable to use a composite rubber latex in which a poly (meth) acrylate rubber component having a main skeleton having a repeating unit of n-butyl acrylate is composited.

The composite rubber latex thus produced by emulsion polymerization can be graft-copolymerized with a vinyl monomer, and the polyorganosiloxane component and poly (meth) acrylic ester rubber in the composite rubber can be graft-copolymerized. The components cannot be extracted and separated with ordinary organic solvents such as acetone and toluene.

The vinyl monomers to be graft-polymerized include methacrylic acid esters such as methyl methacrylate and 2-ethylhexyl methacrylate, aromatic alkenyl compounds such as styrene, α-methylstyrene and vinyltoluene, acrylonitrile and methacrylonitrile. Examples thereof include vinyl cyanide compounds such as, vinyl group compounds containing an epoxy group such as glycidyl methacrylate, vinyl compounds having a carboxylic acid group such as methacrylic acid, and various vinyl monomers such as vinyl acetate. Used in combination of two or more species. Among these monomers, those selected from methyl methacrylate, styrene or acrylonitrile are preferably used.

Emulsion polymerization is used as the graft polymerization method, and the respective components can be mixed and copolymerized in one stage or in multiple stages, or each component can be separately polymerized in multiple stages. From the viewpoint of productivity, it is desirable to polymerize in a single stage.

The amount of the vinyl monomer used in the graft polymerization for obtaining the composite rubber-based graft copolymer is preferably 2 to 20% by weight based on the composite rubber-based graft polymer.
If it is less than 2% by weight, the coagulability tends to be poor even if n-octyl mercaptan is added, and if it is more than 20% by weight, the impact strength developability tends to decrease.

In the present invention, in the presence of a composite rubber latex composed of a polyorganosiloxane component and a (meth) acrylic acid ester rubber component, the vinyl monomer and the vinyl monomer and 100 parts by weight of the vinyl monomer are used in an amount of 0. 1-5 parts by weight n
-A characteristic is that octyl mercaptan is added, and the addition of this alkyl mercaptan makes it possible to obtain a composite rubber-based graft copolymer having both excellent coagulation properties and high impact resistance.

[0036]

After the graft polymerization is completed, the composite rubber-based graft copolymer latex is put into hot water in which a metal salt such as calcium chloride or aluminum sulfate is dissolved and coagulated to give a composite rubber-based graft copolymer. It can be separated and recovered as powder.

In the present invention, salt coagulation is preferred from the emulsifier when producing the polyorganosiloxane latex.

The composite rubber graft copolymer obtained in the present invention is used by adding it to various thermoplastic resins. Examples of various thermoplastic resins include polymers of one or more monomers selected from vinyl chloride resins, aromatic alkenyl compounds, methacrylic acid esters, acrylic acid esters and vinyl cyanide compounds, polyphenylene ether and polystyrene. A mixture of polyacetal resin, polyester resin, polycarbonate resin, polyamide resin,
Examples thereof include polyphenylene sulfide resin, ABS resin, and (co) polymer of ethylenically unsaturated monomer.

Vinyl chloride resin is particularly preferable.

The composite rubber-based graft copolymer of the present invention is
It is desirable to be blended with the thermoplastic resin in the range of 3 to 40% by weight. If it is less than 3% by weight, the effect of improving the impact resistance of the thermoplastic resin is small, and if it exceeds 40% by weight, the impact resistance is good but it is not economical.

The mixing of the composite rubber-based graft copolymer and the thermoplastic resin is usually carried out by a known kneading machine. For example, a mixing roll, a calendar roll, a Banbury mixer, an extruder, a blow molding machine, an inflation molding machine and the like can be mentioned.

If desired, the thermoplastic resin composition of the present invention may contain stabilizers, lubricants, flame retardants, fillers, reinforcing materials, dyes, pigments and the like.

[0044]

The present invention will be described in detail with reference to the following examples.

In the following description, "part" means "part by weight".

The methods for measuring various physical properties in the examples and comparative examples are as follows.

(1) 400 parts of an aqueous solution in which coagulable aluminum sulfate was dissolved at a ratio of 7.5% by weight was heated and stirred at 30 ° C. The obtained composite rubber-based graft copolymer latex was dropped therein and coagulated. Then, the coagulated powder was spread on a 20 # sieve and washed with water, and the powder remaining on the 20 # and the powder passing through the 20 # were dried separately, and the dry weight was measured, and the powder remained on the 20 #. The weight% of the thing was calculated. Those less than 30% by weight were judged to be industrially effective.

(2) Izod impact strength According to the method of ASTM D256. (1/4 ", with notch).

(3) Measurement of number average particle diameter The number average particle diameter of the polyorganosiloxane was measured by a quasi-elastic light scattering method using DLS-700 type manufactured by Otsuka Electronics Co., Ltd.

Reference Example 1 0.5 part of γ-methacryloyloxypropyldimethoxysilane (KBM) and 99.5 parts of octamethylcyclotetrasiloxane (DMC) were mixed to obtain 100 parts of a siloxane mixture. Sodium dodecylbenzene sulfonate (DBSNa)
After adding 300 parts of distilled water in which 0.67 parts were dissolved and stirring for 2 minutes at 10,000 rpm with a homomixer, a homogenizer was passed twice at a pressure of 300 kg / cm @ 2 to obtain a stable premixed organosiloxane emulsion. .

On the other hand, a separable flask equipped with a cooling condenser was placed in dodecylbenzenesulfonic acid (DBSH).
14 parts and 86 parts of distilled water were injected to prepare a 14 wt% dodecylbenzenesulfonic acid aqueous solution.

With the aqueous solution heated to 85 ° C., the premixed organosiloxane emulsion was added dropwise over 2 hours, and after the completion of the addition, the temperature was maintained and cooled for 3 hours.
Then, the reaction product was kept at room temperature for 12 hours and then neutralized with an aqueous solution of sodium hydroxide.

The latex thus obtained (hereinafter referred to as SLX-1) was dried at 170 ° C. for 30 minutes to determine the solid content, which was 18.2% by weight. The number average particle diameter measured by the quasi-elastic light scattering method was 30 nm.

Reference Example 2 To 100 parts of the siloxane mixture shown in Reference Example 1, 200 parts of distilled water in which 1 part of sodium dodecylbenzenesulfonate and 1 part of dodecylbenzenesulfonic acid were dissolved was added, and preliminarily dispersed by a homomixer and homogenized by a homogenizer. Emulsified and dispersed. This premixed organosiloxane emulsion was heated at 80 ° C. for 5 hours, then cooled and neutralized to pH 7 with sodium hydroxide to complete the polymerization.
LX-2 was obtained. The polymerization results are shown in Table 1.

Reference Example 3 A latex SLX-3 was produced in the same manner as in Reference Example 2 except that the composition of the siloxane mixture was changed as shown in Table 1. Table 1 shows the charged composition and the result of polymerization. However, tetraethoxysilane (TEOS) was used as a crosslinking agent.

[0056]

[Table 1]

(Example 1) 27.5 parts of the polyorganosiloxane latex (SLX-1) obtained in Reference Example 1 was sampled in a separable flask, and 265.5 parts of distilled water was added and mixed, followed by n. A mixture of 83 parts butyl acrylate, 2 parts allyl methacrylate, 0.4 parts cumene hydroperoxide was added.

The atmosphere in the flask was replaced with nitrogen by passing a nitrogen stream through the separable flask, and the flask was placed in a water tank and heated to 60 ° C. When the liquid temperature reached 60 ° C, 0.001 parts of ferrous sulfate, 0.003 parts of ethylenediaminetetraacetic acid disodium salt, and 0.25 parts of Rongalit were dissolved in 10 parts of distilled water to add radicals. Polymerization was initiated. This state was maintained for 1 hour to complete the polymerization of the acrylate component to obtain a latex of a composite rubber of polyorganosiloxane and n-butyl acrylate.

2 parts of butyl acrylate, 8 parts of methyl methacrylate, 0.1 part of n-octyl mercaptan,
A mixed solution of 0.05 part of cumene hydroperoxide was added dropwise over 2 hours, and after completion of the addition, the mixture was maintained at 60 ° C. for 2 hours to complete the polymerization, and acrylic acid was added to a composite rubber composed of polydimethylsiloxane and poly n-butyl acrylate. A composite rubber graft copolymer latex obtained by graft-polymerizing butyl and methyl methacrylate was obtained.

By the above coagulation method, a coagulated composite rubber-based graft copolymer (GC-1) was obtained.

Next, 90 parts of a tin vinyl chloride resin consisting of a vinyl chloride polymer having a degree of polymerization of 700, 3.5 parts of dibutyl tin malate, 0.8 part of stearyl alcohol and 0.4 part of a polymer lubricant, and the above composite rubber. Type graft copolymer (G
C-1) and 10 parts were blended and then extruded in the shape of an Izod test piece by a usual method to measure the Izod impact strength. The obtained results are shown in Table 2. (Examples 2 to 3, Comparative Examples 1 to 6 ) With respect to the polyorganosiloxane latex SLX-2 and 3 obtained in Reference Examples 2 and 3, a composite having a composition shown in Table 2 was prepared in the same manner as in Example 1. A rubber-forming reaction and a graft polymerization are carried out to obtain a composite rubber-based graft copolymer GC-2 to G.
C- 9 was obtained. Also, the Izod impact strength of the blend with the vinyl chloride resin was measured. The obtained results are shown in Table 2.

[0062]

[Table 2]

[0063]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to industrially produce a high-impact composite rubber-based graft copolymer having good coagulability and significantly improved productivity, and a thermoplastic resin having excellent impact resistance. It is possible to obtain a remarkable effect that is obtained.

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08F 285/00 C08F 283/12 C08L 51/00

Claims (3)

(57) [Claims] 1. A polyorganosiloxane component and (meth)
In the presence of a composite rubber latex containing an acrylic ester rubber component, 0.1 to 5 parts by weight of n-octyl per 100 parts by weight of the vinyl monomer and the vinyl monomer.
Graft polymerization to obtained composite rubber-based graft copolymer by adding mercaptan. 2. A polyorganosiloxane component and (meth)
In the presence of a composite rubber latex composed of an acrylic ester rubber component, a vinyl monomer and the vinyl monomer 1
The present invention is characterized in that 0.1 to 5 parts by weight of n-octyl mercaptan is added to 100 parts by weight to carry out graft polymerization, and the obtained composite rubber-based graft copolymer latex is coagulated. Method for producing composite rubber-based graft copolymer powder. 3. A polymer of one or more monomers selected from vinyl chloride resins, aromatic alkenyl compounds, methacrylic acid esters, acrylic acid esters and vinyl cyanide compounds, a mixture of polyphenylene ether and polystyrene, At least one thermoplastic resin selected from the group consisting of polyacetal resins, polyester resins, polycarbonate resins, polyamide resins, polyphenylene sulfide resins, ABS resins and (co) polymers of ethylenically unsaturated monomers. A thermoplastic resin composition comprising the composite rubber-based graft copolymer described above.