JPH028209A - Polyorganosiloxane thermoplastic resin - Google Patents

Abstract

PURPOSE:To obtain the subject resin having excellent sliding property, abrasion resistance, weather resistance, freeze resistance, impact resistance, etc., and suitable as a part to be used in cold district, etc., by condensing an organosiloxane with a specific graft-crosslinking agent and graft-polymerizing a vinyl monomer. CONSTITUTION:A modified polyorganosiloxane is produced by condensing (A) 90-99.8wt.% of an organosiloxane having the structural unit of formula I (R<1> is substituted or unsubstituted hydrocarbon group; n is 0-3) (e.g., hexamethylcyclotrisiloxane) and (B) 10-0.2wt.% of a graft-crosslinking agent containing an unsaturated group of formula II (R<2> is H or 1-6C alkyl) and an alkoxysilyl group (e.g., p-vinylphenylmethyldimethoxysilane). The obtained polyorganosiloxane is graft-polymerized with (C) a vinyl monomer (e.g., styrene) to obtain the objective resin containing the component C accounting for preferably 95-20wt.% of the whole polymer composition.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a polyorganosiloxane to which a vinyl monomer is efficiently grafted and which has extremely excellent sliding properties, abrasion resistance, weather resistance, cold resistance, and impact resistance. The present invention relates to thermoplastic resins.

[Conventional technology]

Conventionally, in order to improve the impact strength of thermoplastic resins, a technique of modifying them with rubber has been established.

Examples include ABS resin, which is a styrene-acrylonitrile resin (AS resin) reinforced with butadiene rubber, and AAS resin, which is an AS resin reinforced with acrylic rubber.

Silicone rubber can be considered as such a base rubber component, but if polyorganosiloxane and thermoplastic resin are simply blended, the impact resistance of the resulting blend will be poor due to poor compatibility between these components. It is insufficient. Therefore, a technique is needed to graft vinyl monomers onto rubber like ABS resins, but polyorganosiloxanes generally have poor reactivity with vinyl monomers, making it difficult to form graft copolymers. Several methods have been disclosed for forming this type of graft copolymer. For example, JP-A-50-109282 proposes that a graft copolymer is formed by polymerizing a vinyl monomer in the presence of a polyorganosiloxane containing a vinyl group or an allyl group to improve impact strength. has been done.

Further, JP-A-52-130885 proposes a method for improving the impact strength of a polymer by using a polyorganosiloxane containing a mercapto group instead of a polyorganosiloxane containing a vinyl group or an allyl group.

Furthermore, JP-A-60-252613, JP-A-61
-106614 and JP-A-61136510 disclose that a vinyl heptanomer is polymerized in an emulsion of polyorganosiloxane containing an acrylic group or a methacrylic group, thereby achieving high grafting efficiency and excellent impact strength. It has been proposed to obtain graft copolymers.

[Problem to be solved by the invention]

However, when a polyorganosiloxane containing a vinyl group or an allyl group is used, or when a polyorganosiloxane containing a mercapto group is used, the graft reactivity between the polyorganosiloxane and the vinyl monomer is poor. Therefore, the apparent grafting rate calculated from the amount of gel produced, that is, the ratio of the vinyl polymer grafted to the polyorganosiloxane is small.

Therefore, the interfacial adhesion between the polyorganosilicone and the vinyl polymer is low, resulting in significant delamination, and as a result, there is a problem in that the resulting graft copolymer does not have a good appearance or sufficient impact strength.

In addition, when a polyorganosiloxane containing an acrylic group or a methacrylic group is used, the impact strength of the resulting graft copolymer is improved, but the gloss is low (
A sufficient appearance cannot be obtained.

The present invention was made against the background of the problems of the prior art, and has excellent graft reactivity, weather resistance, cold resistance, slidability,
The purpose of the present invention is to provide a polyorganosiloxane thermoplastic resin with excellent wear resistance.

[Means to solve the problem]

The present invention provides - maximum R' h S i O(4-a)/!
(In the formula, R1 is a substituted or unsubstituted monovalent hydrocarbon group, and n is an integer of O to 3) (hereinafter referred to as "(■) component Grafting cross-agents (sometimes referred to as
■) (hereinafter referred to as “(■) component”)) 10-
Modified polyorganosiloxane (■) obtained by condensing 0.2% by weight [however, (r) + (■) = 100% by weight] (hereinafter sometimes referred to as "component (■)"),
At least one vinyl monomer (■) (hereinafter referred to as “(■)
A polyorganosiloxane-based thermoplastic resin (hereinafter simply referred to as "thermoplastic component") containing a graft copolymer (■) (hereinafter sometimes referred to as "(■) component") obtained by graft polymerization of (sometimes referred to as "plastic resin").

The organosiloxane (1) used in the present invention has a structural unit represented by the above-mentioned maximum, and has a linear, branched or cyclic structure, but is preferably an organosiloxane having a cyclic structure. be.

The substituted or unsubstituted monovalent hydrocarbon group possessed by this organosiloxane (I) includes, for example, a methyl group, an ethyl group, a propyl group, a vinyl group, a phenyl group, and substitutions thereof with a halogen atom or a cyano group. Examples include hydrocarbon groups.

Further, in the average compositional formula, the value of n is an integer of 0 to 3.

Specific examples of organosiloxane (1) include cyclic compounds such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, and trinotyltriphenylcyclotrisiloxane. , linear or branched organosiloxanes.

The organosiloxane (1,) may be a precondensed polyorganosiloxane having, for example, a weight average molecular weight of about 500 to 10,000 in terms of polystyrene.

In addition, when the organosiloxane (1) is a poly-organosiloxane, the molecular chain terminal thereof is blocked with, for example, a hydroxyl group, an alkoxy group, a trimethylsilyl group, a dimethylvinylsilyl group, a methylphenylvinylsilyl group, a methyldiphenylsilyl group, etc. may have been done.

Next, the graft cross-agent (n) used in the present invention is a compound having both an unsaturated group represented by the above-mentioned maximum and an alkoxysilyl group.

The above-maximum R2 is a hydrogen atom or a carbon number of 1 to
60 furkyl group, but hydrogen atom or carbon number 1-2
is preferably an alkyl group, more preferably a hydrogen atom or a methyl group.

These compounds specifically include p-vinylphenylmethyldimethoxysilane, 1-(m-vinylphenyl)methyldimethylisopropoxysilane, 2-(p-vinylphenyl)ethylenemethyldimethoxysilane, and 3-(m-vinylphenyl)methyldimethylisopropoxysilane.
(p-vinylphenoxy)propylmethyljethoxysilane, 3(p-vinylbenzoyloxy)propylmethyldimethoxysilane, 1-(0-vinylphenyl)-1
, 1,2-1-dimethyl-2,2-dimethoxydisilane, 1-(p-vinylphenyl)-1,1-diphenyl-
3-ethyl-3,3-jethoxydisiloxane, m-vinylphenyl-(3-(triethoxysilyl)propyl)diphenylsilane, (3-<p-isopropenylbenzoylamino)propyl]phenyldipropoxysilane, etc. In addition to these, mixtures thereof can also be mentioned.

The grafting agent (n) is preferably p-vinylphenylmethyldimethoxysilane, 2(p-vinylphenyl)ethylmethyldimethoxysilane, or 3-(p-vinylbenzoyloxy)propylmethyldimethoxysilane, more preferably is p-vinylphenylmethyldimethoxysilane.

The proportion of this grafting cross-agent used is component (1) and component (II).
) in the total amount of components, 0.2 to 10% by weight, preferably 0
．． 5 to 5% by weight, and if it is less than 0.2% by weight, a high grafting rate cannot be obtained in the graft polymerization of the resulting modified polyorganosiloxane (III) and the monomer (IV), and as a result, the modified polyorganosiloxane (I
The interfacial adhesion between n) and the grafted vinyl polymer decreases, delamination occurs, and the graft copolymer (V) cannot have sufficient impact strength.

On the other hand, when the proportion of the graft cross-agent (II) exceeds 10% by weight, the grafting rate increases, but the polymerization of the grafted vinyl polymer decreases as the graft cross-agent (II) increases, and this causes the vinyl polymer to decrease. As a result, sufficient impact strength cannot be obtained.

The modified polyorganosiloxane (III) is produced by shear mixing the organosiloxane (1) and the grafting agent (■) using a homomixer in the presence of an emulsifier such as alkylbenzenesulfonic acid, and then condensing the organosiloxane (III). can be manufactured. This emulsifier acts as an emulsifier for organosiloxane (1) and also serves as a condensation initiator.

The amount of the emulsifier used is usually about 0.1 to 5% by weight, preferably about 0.3 to 3% by weight, based on the total amount of components (1) and (II).

The amount of water used at this time is the amount of water used for component (1) and (II).
) It is usually 100 to 500 parts by weight, preferably 200 to 400 parts by weight, per 100 parts by weight of component.

Moreover, the condensation temperature is usually 5 to 100°C.

Incidentally, during the production of the modified polyorganosiloxane (■), a crosslinking agent may be added as a third component in order to improve the impact resistance of the resulting resin. Examples of the crosslinking agent include trifunctional crosslinking agents such as methyltrimethoxysilane, phenyltrimethoxysilane, and ethyltriethoxysilane, and tetrafunctional crosslinking agents such as tetraethoxysilane. The amount of this crosslinking agent added is usually 10% by weight or less, preferably 5% by weight or less, based on the total amount of organosiloxane (1) and grafting agent (II).
It is about % by weight or less.

In addition, the weight average molecular weight of the modified polyorganosiloxane (I[[> in terms of polystyrene) obtained in this way is
Usually, it is about 30,000-1,000.000, preferably about 50,000-300.000.

Next, the polyorganosiloxane thermoplastic resin of the present invention containing the graft copolymer (V) is obtained by rag-graft polymerizing the modified polyorganosiloxane (III) obtained in this way with the monomer (IV). can get.

As the vinyl monomer (IV) used in the present invention,
For example, aromatic alkenyl compounds such as styrene, α-methylstyrene, sodium styrene sulfonate; methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, butyl methacrylate, allyl methacrylate: methyl acrylate, ethyl acrylate, butyl Acrylic acid esters such as acrylate, hydroxyethyl methacrylate, dimethylaminoethyl methacrylate; vinyl cyanide compounds such as acrylonitrile, methacrylonitrile; olefins such as ethylene, propylene; conjugated diolefins such as butadiene, isoprene, chloroprene; and vinyl acetate, chloride Examples include vinyl, vinylidene chloride, triallylisocyanurate, acrylic acid, methacrylic acid, N-phenylmaleimide, N-cyclohexylmaleimide, maleic anhydride, and these may be used alone or in combination.

Among these vinyl monomers (TV), those containing 65 to 75% by weight of styrene and 35 to 25% by weight of acrylonitrile are used for the purpose of further improving the impact resistance of the polyorganosiloxane thermoplastic resin of the present invention. is preferred.

In addition, the charging composition when graft polymerizing the vinyl monomer (1'/) to the modified polyorganosiloxane (III) is 5-80% by weight of the (I[[) component, preferably 10-80% by weight.
60% by weight, component (IV) 95-20% by weight, preferably 90-40% by weight [however, (111)+(IV)=
(100% by weight), if component (1) is less than 5% by weight, sufficient impact strength cannot be obtained, and if it exceeds 80% by weight, the proportion of vinyl polymer to be grafted decreases, and as a result, the modified polyester Sufficient interfacial adhesion cannot be obtained between the organosiloxane (1) and the vinyl polymer, resulting in poor appearance and reduced impact strength of the resulting thermoplastic resin.

In addition, the graft copolymer (V) obtained in this way
The grafting rate is usually 20% by weight or more, preferably 8% by weight or more.
It is about 0% by weight or more, more preferably about 100% by weight or more. As described above, when the grafting rate of the graft copolymer (V) is high, the interfacial adhesion between the graft copolymer (V) and the vinyl polymer that has not been directly grafted increases, so that A thermoplastic resin in which the modified polyorganosiloxane <m) is uniformly dispersed and has a good appearance and excellent impact strength is obtained.

Furthermore, the thermoplastic resin of the present invention contains, in addition to the graft copolymer (V) thus obtained, a vinyl polymer which is a polymer of ungrafted vinyl monomer (IV). It contains the graft copolymer (V) in an amount of 5% by weight or more, preferably 10% by weight or more.

When producing the thermoplastic resin of the present invention, a composition containing the graft copolymer (V) is obtained by graft polymerizing the modified polyorganosiloxane (1) with the monomer (IV) by normal radical polymerization. .

Here, depending on the type of radical polymerization initiator, it is necessary to neutralize the latex of the modified polyorganosiloxane (1), which has been made acidic by the alkylhenzenesulfonic acid, with an alkali as described above. As this alkali, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, triethanolamine, triethylamine, etc. are used.

In addition, as a radical polymerization initiator, for example, an oxidizing agent consisting of an organic hydroperoxide such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, para-menthane hydroperoxide, a sugar-containing iron pyrophosphate formulation, or a sulfoxylate formulation. , Redox system initiator in combination with a reducing agent such as a mixed formulation of sugar-containing iron pyrophosphate formulation/sulfoxylate formulation; Persulfates such as potassium persulfate and ammonium persulfate: Azobisisobutyronitrile, dimethyl 2 .Azo compounds such as 2'-azobisisobutyrate and 2-carbamoylazaisobutyronitrile; and organic peroxides such as benzoyl peroxide and lauroyl peroxide, preferably for initiation of the redox system. It is a drug.

The amount of these radical polymerization initiators used is usually 0.00 parts by weight per 100 parts by weight of the vinyl monomer (IV) used.
05 to 5 parts by weight, preferably 0.1 to 3 parts by weight.

As the radical polymerization method at this time, it is preferable to carry out emulsion polymerization or solution polymerization.

During emulsion polymerization, known emulsifiers, the aforementioned radical initiators, chain transfer agents, and the like are used.

Here, as the emulsifier, anionic emulsifiers such as sodium dodecylbenzene sulfonate, sodium lauryl sulfate, sodium diphenyl ether disulfonate, sodium dialkali succinate ester sulfonate, or polyoxyethylene alkyl ester, polyoxyethylene alkyl allyl ether One or more nonionic emulsifiers may be used.

The amount of emulsifier used is as follows:
Usually, it is about 0.5 to 5% by weight.

As a chain transfer agent, t-dodecylmercaptan, octylmercaptan, n-tetradecylmercaptan, n
-Mercaptans such as hexyl mercaptan; halogen compounds such as carbon tetrachloride and ethylene bromide are usually used in an amount of 0.02 to 1% by weight based on the vinyl monomer (IV).

During emulsion polymerization, in addition to radical polymerization initiators, emulsifiers, chain transfer agents, etc., various electrolytes and pH
Vinyl monomer (IV) 100
Usually 100 to 500 parts by weight of water,
Emulsion polymerization is carried out using the radical polymerization initiator, emulsifier, chain transfer agent, etc. in amounts within the above range, at a polymerization temperature of 5 to 100°C, preferably 50 to 90°C, and a polymerization time of 0.1 to 10 hours. Ru.

In the case of emulsion polymerization, a vinyl monomer (IV) and a radical initiator are added to a latex containing a modified organopolysiloxane (III) obtained by condensation of an organosiloxane (1) and a grafting agent (II). It can also be implemented by adding.

On the other hand, in the case of solution polymerization, the modified polyorganosiloxane (■) and the vinyl monomer (IV) are dissolved in an organic solvent, and a radical initiator, a chain transfer agent if necessary, and various additives are added thereto to form a radical. Polymerize.

Examples of the organic solvent used in this solution polymerization include toluene, n-hexane, cyclohexane, chloroform, and tetrahydrofuran.

During solution polymerization, vinyl monomer (IV) is
1001 (Usually, the organic solvent is 80 to 50%
0 parts by weight, and the radical polymerization initiator, chain transfer agent, etc. are used in amounts within the above ranges, and the solution polymerization is carried out at a polymerization temperature of 5 to 150°C, preferably 50 to 130°C, and a polymerization time of 1 to 10 hours. be done.

In the case of this solution polymerization, impurities can be reduced more significantly than in the case of emulsion polymerization.

When the polyorganosiloxane thermoplastic resin of the present invention is produced by emulsion polymerization, it is purified by coagulating it by a conventional salt coagulation method, washing the obtained powder with water, and then drying it.

In addition, in the case of solution polymerization, unreacted monomers and solvent are distilled off using steam vapor, and the resulting resin mass is crushed and dried to refine the resin.

The thermoplastic resin of the present invention containing the graft copolymer (V) obtained by these methods can be pelletized with a kneader such as an extruder.

At this time, other known polymers may be used depending on the required performance.
Usually, they may be blended in an appropriate amount of 99% by weight or less, preferably 90% by weight or less, and used as a thermoplastic resin composition (hereinafter simply referred to as "thermoplastic resin composition").

Examples of such polymers include polybutadiene, butadiene-styrene copolymer, acrylonitrile-butadiene copolymer, polyisoprene, diene rubber such as natural rubber; acrylic rubber/ethylene-propylene copolymer, ethylene-propylene- Olefin rubbers such as diene copolymers, chlorinated butyl rubber, and chlorinated polyethylene; styrene-butadiene broth copolymers, styrene-
Aromatic vinyl-conjugated diene block copolymers such as butadiene-styrene block copolymers and styrene-butadiene-styrene radial terebrosulfate copolymers; hydrogenated products of the block copolymers; polypropylene, polyethylene, polystyrene, styrene- Acrylonitrile copolymer, rubber reinforced polystyrene (HIPS), acrylonitrile-butadiene-styrene resin (ABS resin), acrylonitrile-ethylenepropylene-styrene resin (A
BS resin), methyl methacrylate-butadiene-styrene resin (MBS resin), acrylonitrile-butadiene-methyl methacrylate-styrene resin, acrylonitrile-n-butyl acrylate-styrene resin (AAS resin), polyvinyl chloride, polycarbonate, polyethylene terephthalate , polybutyl terephthalate, polyacetal, polyamide, epoxy resin, vinylidene polyfluoride, polysulfone, ethylene-vinyl acetate copolymer, PPS resin, polyetheretherketone, PPO resin, styrene-methyl methacrylate copolymer, styrene-maleic anhydride Examples include acid copolymers, rubber-modified PPO resins, styrene-maleimide F-based copolymers, rubber-modified styrene-maleimide-based copolymers, polyamide-based elastomers, and polyester-based elastomers.

The pelletized thermoplastic resin (composition) is processed and molded by conventional means such as compression molding and injection molding.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that parts and % in the examples are parts by weight and % by weight unless otherwise specified.

In addition, various measurement items in the examples were as follows.

That is, the grafting rate and grafting efficiency were determined by the following methods.

A certain weight (X) of the graft polymerization product was placed in acetone, shaken for 2 hours using a shaker to dissolve the free copolymer, and then heated using a centrifuge at a rotation speed of 23. 00 or
Centrifuge at pm for 30 minutes to obtain insoluble matter. Next, it was dried at 120° C. for 1 hour using a vacuum dryer to obtain the weight of insoluble matter (y), and the grafting rate and grafting efficiency were calculated using the following formula.

X100 (%) X100 (%) The physical properties of the thermoplastic resin (composition) were evaluated according to the following evaluation method (a) or (b).

(Leaving space below) Evaluation method (a) Evaluation 1αμL Eyu) *Falling weight impact strength Using a DuPont impact tester, the R of the tip of the striking rod =
Dropped from a height of 50cm with 1/2", Atsumi 3.2111
The falling weight impact strength of the molded product No. 1 was measured.

The unit is kl/bi.

*Sliding characteristics Friction and wear tests were conducted using a precious wood type sliding testing machine, and the same material or steel (345C) was used as the mating material. The test piece used was a hollow cylindrical piece with an outer diameter of 25.6 mm and an inner diameter of 20.0 mm, and the mating material was also of the same shape.

The measurement conditions for the coefficient of dynamic friction were a load of 5 kg and a running speed of 3.75 cm/sec in an atmosphere with a room temperature of 23° C. and a humidity of 50%.

The coefficient of dynamic friction is calculated using the following formula.

3xFx (rt"-rl") (In the formula, μ is the coefficient of dynamic friction, F is the force applied to the load cell, P is the load, R is the arm length to the load cell, rl is the inner diameter, and 2 represents the outer diameter.) Wear The measurement conditions for the coefficient are a room temperature of 23°C and a humidity of 50%, with a load of 5 ksr and a running speed of 3.7 for the same material.
5cm/sec, 12.600 rotations (running speed 0.24km)
), and in the case of steel (345C), load 1
0kg, running speed 15c+a/sec, so, ooo rotation (
Measurements were made at a running speed of 6 kg+).

The friction coefficient is calculated using the following formula.

Px l × α (where A is the coefficient of friction, ΔW is the change in weight of the sample, P
is the load, l is the traveling distance, and α is the density of the sample.) *Weather resistance test method Sunshine Weather Meter (manufactured by Toyo Rika, WE-
After 200 hours of exposure (63° C., with rain), the Izod impact strength was measured.

Example 1 1.5 parts of p-vinylphenylmethyldimethoxysilane and 98.5 parts of octamethylcyclotetrasiloxane were mixed, and this was added to 300 parts of light water in which 2.0 parts of dodecylbenzenesulfonic acid was dissolved. The mixture was stirred for 3 minutes using a mixer to emulsify and disperse the mixture.

This mixed solution was transferred to a separable flask equipped with a condenser, a nitrogen inlet, and a stirrer, heated at 90° C. for 6 hours while stirring and mixing, and cooled at 5° C. for 24 hours to complete condensation.

The condensation rate of octamethylcyclotetrasiloxane in the obtained modified polyorganosiloxane (nI) was 92.8%.
Met.

This modified polyorganosiloxane latex was neutralized to pH 7 with an aqueous sodium carbonate solution.

35 parts of this modified polyorganosiloxane latex in terms of solid content, 0.5 parts of sodium dodecylbenzenesulfonate, and 140 parts of light water were mixed into a separable flask equipped with a dropping bottle, a condenser, a nitrogen inlet, and a stirrer. Furthermore, 15.81 parts of styrene corresponding to 34% of the total amount of styrene, 6.29 parts of acrylonitrile corresponding to 34% of the total amount of acrylonitrile, 0.2 part of sodium pyrophosphate, and 7')'tj! Add 0.25 parts, sulfuric acid cylinder-i + 0.004 parts and 0.074 parts of cumene hydroperoxide, and heat at 70°C while flowing nitrogen.
The temperature rose to . After polymerization for 1 hour, remaining styrene 30.6
9 parts, remaining 12.2 parts of acrylonitrile, 1.084 parts of sodium dodecylbenzenesulfone, 42 parts of light water, 0.12 parts of cumene hydroperoxide, and t-
A mixture of 0.06 parts of dodecyl mercaptan was added over 3 hours using a dropping bottle. After the dropwise addition was completed, the polymerization reaction was carried out for 1 hour, and after the polymerization was completed, the mixture was cooled.

The obtained graft copolymer latex was poured into hot water in which 2 parts of calcium chloride dihydrate was dissolved, and salting out coagulation was performed to separate the thermoplastic resin containing the graft copolymer. This thermoplastic resin was thoroughly washed with water and then dried at 80° C. for 16 hours to complete purification.

Next, 57% of this thermoplastic resin powder was mixed with 43% of a copolymer (AS resin) obtained by emulsion polymerization at a monomer charge ratio of styrene and acrylonitrile of 75:25, and the thermoplastic resin was A composition was prepared.

This thermoplastic resin composition was extruded using a two-wheel extruder at a cylinder temperature of 230°C to obtain pellets.

The obtained thermoplastic resin composition had excellent cold resistance, weather resistance, sliding properties, impact resistance, and appearance. The evaluation results are shown in Table 1.

Examples 2 to 3 and Comparative Examples 1 to 2 Example 1 except for changing the blending ratio of polyorganosiloxane (1) and graft cross-agent (I[) in Example 1.
A thermoplastic resin containing a modified polyorganosiloxane latex and a graft copolymer was prepared in the same manner as in Example 1, and a thermoplastic resin composition was prepared in the same manner as in Example 1 using this thermoplastic resin.

The results are shown in Table 1.

In Comparative Example 1, the amount of the grafting cross-agent was 0.1%, the grafting rate decreased, and sufficient impact strength could not be obtained.

In addition, in Comparative Example 2, the amount of graft cross-agent was 15
%, the molecular weight of the vinyl polymer grafted to the modified polyorganosiloxane and the vinyl polymer not grafted decreased, and sufficient impact strength could not be obtained.

Comparative Examples 3 to 5 During the preparation of modified polyorganosiloxane (II[), p
- instead of vinylphenylmethyldimethoxysilane,
A modified polyorganosiloxane latex and a graft copolymer were prepared in the same manner as in Example 1, except that 1.5 parts each of vinylmethyldimethoxysilane, T-mercaptopropylmethyldimethoxysilane, or γ-methacryloxypropylmethyldimethoxysilane was used. A thermoplastic resin and a thermoplastic resin composition containing (V) were prepared.

These thermoplastic resins were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

In both Comparative Examples 3 and 4, a high grafting rate was not obtained and sufficient impact strength was not obtained.

Further, in Comparative Example 5, the same impact strength as Example 1 was obtained, but the appearance was poor and sufficient gloss was not obtained.

Examples 4 to 6 Other than changing the vinyl monomer (TV) grafted to the modified polyorganosiloxane (1) as shown in Table 1, and changing the resin blended into the obtained thermoplastic resin as shown in Table 1. A thermoplastic resin composition was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

As is clear from Table 1, the graft copolymer (V) had a high graft ratio, and a thermoplastic resin composition with good impact strength and appearance was obtained.

Examples 7-8 Except for changing the graft cross-agent as shown in Table 1,
A thermoplastic resin and a thermoplastic resin composition were prepared and evaluated in the same manner as in Example 1.

The results are shown in Table 1.

As is clear from Table 1, the graft copolymer (V) had a high graft ratio, and a thermoplastic resin composition with good impact strength and appearance was obtained.

Example 9 and Comparative Example 6 In Example 9, a thermoplastic resin composition consisting of 51% of the thermoplastic resin obtained in Example 1 and 49% of the AS resin used in Example 1 was prepared in the same manner as in Example 1. This is a resin molded using the following method.

The content of modified polyorganosiloxane (1) in the thermoplastic resin composition of Example 9 was 17.85%.

On the other hand, in Comparative Example 6, ABS resin (manufactured by Japan Synthetic Rubber 0S),
JSRABS12), and the content of butadiene rubber in this resin was 17.8%.

Using these resins, physical properties were compared according to the evaluation methods (a) and (b) above.

The results are shown in Table 2.

The thermoplastic resin of the present invention has particularly excellent cold resistance, weather resistance, and sliding properties compared to existing ABS resins, and has other physical properties that are equal to or better than that, and has extremely excellent performance. I understand.

Table 2 Examples 1O to 11 In these examples, the thermoplastic resin of the present invention was molded and evaluated without blending it with any other resin. The polymerization conditions, molding conditions, and evaluation conditions are the same as in Example 1. The results are shown in Table 3.

As is clear from Table 3, a graft copolymer with a high graft ratio was obtained, and a thermoplastic resin with good impact strength and appearance was obtained.

〔Effect of the invention〕

The thermoplastic resin of the present invention uses a modified polyorganosiloxane bonded with a specific graft cross-agent to graft-polymerize vinyl monomers, and graft polymerization of vinyl monomers is faster than that using conventional polyorganosiloxanes. This includes a graft copolymer that is more likely to occur and has a much higher grafting rate and grafting efficiency. the result,
A thermoplastic resin containing the graft copolymer of the present invention, or a resin composition consisting of this and another resin, has excellent balance of physical properties. In particular, it has excellent weather resistance, cold resistance, sliding properties, and abrasion resistance, and its sliding properties and abrasion resistance are better than polyacetal and polyamide, which are known as sliding materials. In addition, other physical properties are similar to or better than ABS resin, which is known to have well-balanced physical properties.

Because the thermoplastic resin of the present invention has these excellent properties, it can be applied to new fields of use such as sliding parts, parts for cold regions, parts for outdoor use, etc., and its industrial significance is extremely large. It is.

Patent applicant: Japan Synthetic Rubber Co., Ltd. Same Toshiba Silicone Corporation Agent: Patent Attorney Takashi Shirai Procedural amendment (voluntary) July 7, 1999

Claims (1)

[Claims] (1) General formula R^1_nSiO_(_4_-_n_)_
Organosiloxane (I) 90-99 having a structural unit represented by /_2 (wherein R^1 is a substituted or unsubstituted monovalent hydrocarbon group, and n represents an integer of 0 to 3)
．． 8% by weight, and the general formula ▲ includes mathematical formulas, chemical formulas, tables, etc. ▼ (in the formula, R^
2 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms)
A modified polyorganosiloxane (III) obtained by condensing 10 to 0.2% by weight of a graft cross-agent (II) having both an unsaturated group represented by and an alkoxysilyl group,
A polyorganosiloxane thermoplastic resin containing a graft copolymer (V) obtained by graft polymerizing at least one vinyl monomer (IV).