JP2687319B2 - Impact resistance improving agent for polyester resin and polyester resin composition containing the improving agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an impact resistance improver for polyester resin and a polyester resin composition containing the improver.

BACKGROUND ART Polyester resins are widely used for various molded products such as sheets, films and bottles because of their excellent physical properties and processing suitability. Corresponding physical properties are required for these molded products in relation to their intended use, and one of the important physical properties is impact resistance. Particularly in recent years, since the shape of molded products is becoming more complicated and the wall thickness is made thinner, it is possible to improve impact resistance without deteriorating the physical properties such as proper working property, heat resistance and weather resistance. It is becoming more and more demanding.

The present invention relates to an impact resistance improver for a polyester resin which meets the above requirements, and a polyester resin composition which does not contain the improver.

<Conventional Technology and Its Problems> Conventionally, as a means for improving the impact resistance of a polyester resin, an example in which a polymer mainly containing a hydrocarbon is blended has been proposed. For this, examples using an ABS resin or a modified ABS resin (Japanese Patent Laid-Open Nos. 50-23448, 54-40851, and 56-56)
-14546), an example using EPDM (JP-A-59-176344), an example using a specific rubber-like vinyl polymer (JP-A-58-4525).
6), an example using a hydrocarbon polymer having an epoxy group (JP-A-52-32045) and the like. Further, an example of blending a thermoplastic resin has been proposed. Examples thereof include the case where the above-mentioned polymer mainly composed of hydrocarbon and polycarbonate are used in combination (Japanese Patent Publication No. 54-37632, Japanese Unexamined Patent Publication No. 52-50367, Japanese Unexamined Patent Publication No. 57-16034). Further, an example of blending a polysiloxane derivative has been proposed. The bonding form of the modifying group to the silicon atom of the polysiloxane is -Si-O.
Example using modified polysiloxane which is --CO--
-207922), an example using an epoxy-modified polysiloxane (JP-A-62-152451, JP-A-62-179558), an example in which a polycarbonate in which a polysiloxane segment is copolymerized and a butadiene / methyl methacrylate / styrene copolymer are used in combination. (EP Patent Publication 105388), an example using a styrene-grafted polysiloxane copolymer (German Patent Publication)
2659357) etc. In addition, examples have been proposed in which a diene hydrocarbon polymer is hydrogenated or a diene hydrocarbon polymer modified with a saturated monomer is blended.

However, in the conventional means as exemplified above, the degree of improvement in impact resistance, particularly the degree of improvement in impact resistance at low temperature is insufficient, or the heat resistance and weather resistance of the polyester resin are impaired, Alternatively, there is a problem that the viscosity increases during melt-kneading with the polyester resin, which impairs the processability.

<Problems to be Solved by the Invention and Means for Solving the Problems> The present invention provides a new impact resistance improving agent for polyester resin and the improving agent, which solves the above-mentioned conventional problems and meets the above-mentioned requirements. The present invention relates to a polyester resin composition formed by blending.

However, as a result of research from the above viewpoints, the present inventors have found that a specific polysiloxane / polyester copolymer is correctly suitable as an impact resistance improver for polyester resin,
The inventors have found that a composition in which a predetermined amount of the improving agent is blended with a polyester resin can remarkably improve impact resistance without deteriorating the physical properties and processing suitability inherent in the polyester resin, and have completed the present invention.

That is, the present invention has a polysiloxane block having a molecular weight of 4000 to 70,000 in the molecule and a polyester block represented by the following formula 1 directly bonded to a silicon atom of the polysiloxane block, and the ratio of both is polysiloxane block / polyester. An impact resistance improver for a polyester resin comprising a polysiloxane / polyester copolymer having a block of 20 to 80/80 to 20 (each weight%), and the impact resistance improver to the polyester resin in an amount of 0.2 to 7 weight%. The present invention relates to a polyester resin composition formed by blending.

[However, m is an integer of 1 to 6. n is an integer of 1 to 400.
a is an integer of 1 to 6. R ¹¹ is H or an alkyl group having 1 to 6 carbon atoms. R ² is an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 1 to 18 carbon atoms, a benzyl group, or 2 to 18 carbon atoms.
Acyl group. In the present invention, the polysiloxane / polyester copolymer is a copolymer having a polysiloxane block and a polyester block mainly composed of a ring-opening polymer of a cyclic lactone in the molecule. The copolymer can be roughly classified into the following methods.

1) A ring-shaped lactone is directly subjected to ring-opening polymerization to a modified polysiloxane having an alcoholic hydroxyl group, and the hydroxyl group at the polymer terminal is etherified with an alkyl halide or acylated with an organic carboxylic acid or an ester-forming derivative thereof. .

2) A ring-opening polymer of a cyclic lactone, which has a reactive group such as a carboxyl group, a hydroxyl group or an ethylenically unsaturated double engagement at one end, and a functional group which reacts with the reactive group. React with the modified polysiloxane having.

The polysiloxane / polyester copolymer produced by the above method is obtained by directly connecting the silicon atom of the polysiloxane block with the polyester block represented by the above formula 1, and among the polyester blocks of the formula 1, In, the polyester block in which m is 4, a is 3, and R ¹ is H is preferable.

The modified polysiloxane used for producing the copolymer of the present invention includes a hydro-modified polysiloxane having a Si-H bond, and various modified polysiloxanes having a functional group bonded to a silicon atom via an alkylene group. There are polysiloxanes, and more specific examples thereof include alcohol-modified polysiloxanes having a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, etc. Among them, they are easy to produce and have heat resistance themselves. Hydro-modified polysiloxane, because it is excellent
Alcohol-modified polysiloxane is industrially advantageous. In this case, the functional group may be at the end of the molecular chain of the modified polysiloxane or may be located in the middle of the molecular chain,
Further, even if the main chain in the modified polysiloxane is a polydimethylsilicon chain, its methyl group is partially substituted with an aromatic group such as an alkyl group having 2 to 18 carbon atoms, a phenyl group, a styryl group, and a methylstyryl group. It does not matter even if it was done.

On the other hand, examples of the cyclic lactone used for producing the copolymer of the present invention include δ-propiolactone, δ-valerolactone and ε-caprolactone.
Among them, ε-caprolactone is industrially advantageous.

The copolymer of the present invention has a ratio of both blocks of polysiloxane block / polyester block = 20 to 80/80.
.About.20 (each weight%), preferably 30 to 70/70 to 30 (each weight%), and the polysiloxane block has a molecular weight in the range of 4000 to 70,000. When the ratio of both blocks is out of the range of polysiloxane block / polyester block = 20 to 80/80 to 20 (each weight%),
When the molecular weight of the polysiloxane block is out of the range of 4000 to 70,000, the dispersibility of the resulting copolymer in the polyester resin is poor and it becomes difficult to knead them, or the molded product finally obtained from the kneaded product. It is inconvenient because the surface is contaminated with bleed or the desired impact resistance cannot be obtained.

Further, the copolymer of the present invention has a blocked hydroxyl group in the molecule, as is apparent from the above-mentioned production method. When a hydroxyl group is present in the copolymer, the polyester resin is liable to undergo transesterification or decomposition during heating when the copolymer is kneaded with the polyester resin or when the kneaded product is molded. This is inconvenient because the physical properties and workability are impaired.

Specific examples of the copolymer of the present invention include the following S-1 to S-4.

Note) In S-1 to S-4, Although the copolymer of the present invention has been described above, in the present invention, the polyester resin composition is formed by mixing the polyester resin with a predetermined amount of the copolymer.

The polyester resin is a polyester resin produced by polycondensation of a dibasic acid and a diol or polycondensation of an oxycarboxylic acid. In this case, examples of the dibasic acid include terephthalic acid, isophthalic acid, phthalic acid, aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, and ester-forming derivatives thereof. As the diol, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol,
Aliphatic or alicyclic diols such as diethylene glycol, triethylene glycol, polyethylene glycol and polytetramethylene glycol, aromatic diols such as dihydroxyethoxybenzene and dihydroxyethoxybisphenol A, and the like, but hydroquinone,
Dihydric phenols such as catechol and naphthalene-2,6-diol, and trimellitic acid and trimethylolpropane can be used as long as a substantially linear polymer can be obtained. Examples of compounds used in the polycondensation of oxycarboxylic acid or its ester-forming derivative include p-hydroxybenzoic acid, 2,6-oxynaphthoic acid and p-oxyethoxybenzoic acid.

The polyester resin used in the present invention is a single product or a mixed product of two or more kinds obtained by polycondensation of the compounds as exemplified above, and among them, polybutylene terephthalate and polyethylene terephthalate are industrially advantageous.

The blending amount of the copolymer of the present invention with respect to the polyester resin is 0.2 to 7% by weight in order to allow the molded product of the polyester resin to have sufficient impact resistance while providing the original properties of the polyester resin. It is preferably 5% by weight.

A known method can be applied to the method of blending the copolymer of the present invention with the polyester resin. Among them, there are a method of previously dry blending the polyester resin and the copolymer, a method of directly kneading both with a uniaxial or biaxial extruder, and a method of similarly preliminarily mastering both. It is advantageous for improvement.

The polyester resin composition of the present invention comprises the polyester of the present invention and 0.2 to 7% by weight of the copolymer of the present invention. However, other additives may be used in combination within a range not impairing the effects of the present invention. You can also This includes thermoplastic resins such as polyphenylene ether and polycarbonate, reinforcing fibers such as glass fibers and carbon fibers, whiskers and the like, inorganic fillers such as carbon calcium and silica, lubricants and mold release agents such as liquid paraffin and metal stearate. In addition, there are plasticizers, antistatic agents, antioxidants, weathering agents, crystallization rate adjusting agents, and the like, and these are preferably used in combination within the range of 50% by weight or less of the polyester resin composition.

Examples will be given below to make the present invention clearer, but it goes without saying that the present invention is not limited to these Examples.

<Examples, etc.> Test Category 1 (Production Example of Copolymer) Production Example of Polysiloxane / Polyester Copolymer (S-1 to S-4) According to the Present Invention and Polysiloxane / Polyester Copolymer for Comparison The production examples of the polymers (R-1 to R-6) are shown below. The copolymers S-1 to S-4 correspond to the copolymers having the respective symbols described above.

.. Production of S-1 350 g of modified polydimethylsiloxane having a hydroxypropyl group at both ends (molecular weight 8500, hereinafter referred to as bishydroxypropyl modified polydimethylxane at the end) was charged into a reaction vessel, and the inside of the reaction vessel was filled with nitrogen. Replaced. The contents were heated to 150 ° C, and ε-caprolactone 3 was added with stirring.
50 g was gradually added dropwise. After the completion of dropping, the mixture was aged at 160 ° C for 5 hours, cooled to 70 ° C, and 8.4 g of acetic anhydride was added.
Warmed to 140 ° C. After aging for 3 hours, the produced acetic acid was removed under reduced pressure to obtain S-1. S-1 molecular weight approx. 14,000
(GPC method, polystyrene conversion value, molecular weight of copolymer produced was measured by the same method below), hydroxyl value was 0.7, and acid value was 0.6.

..Production of S-2 By the same operation as that of S-1, bishydroxypropyl-modified polydimethylsiloxane having a terminal (molecular weight 5000)
A copolymer was obtained by reacting 350 g with 350 g of ε-caprolactone. 500 g of this copolymer and 6.3 g of potassium hydroxide were charged into an autoclave, and after nitrogen substitution, the mixture was stirred and dispersed at 130 ° C., and 5.67 g of methyl chloride was gradually introduced at 140 ° C. for reaction. After the reaction was completed, it was aged for 3 hours. The product was washed with water and the by-produced salt was removed to obtain S-2. The molecular weight of S-2 was about 9500 and the hydroxyl value was 1.0.

.. Production of S-3 By the same operation as in the case of S-1, bishydroxymethylphenyl-modified polydimethylsiloxane having a terminal (molecular weight
14000) 350 g was reacted with 350 g of ε-caprolactone to obtain a copolymer. Charge 500 g of this copolymer, 3.2 g of pyridine and 500 g of toluene, and add 5.6 g of benzoyl chloride at room temperature.
Was gradually added dropwise. After completion of dropping, the mixture was aged at 50 ° C for 1 hour. The product was washed with water and desolvated to give S-3. S-3
Had a molecular weight of about 2500, a hydroxyl value of 0.9, and an acid value of 0.7.

.. Production of S-4 10 g of allyl alcohol and 0.1 g of hydroquinone were reacted with 1893 g of .epsilon.-caprolactone in the same manner as in the case of S-1 to obtain a polycaprolactone adduct. And hydro-modified polydimethylsiloxane (molecular weight 1100
0) 350g, hexachloroplatinic (IV) acid-6 as a catalyst
In the presence of 0.15 ml of hydrate (6% isopropyl alcohol solution), 458 g of the above polycaprolactone adduct was added at 130 ° C. for 4 hours.
The reaction was carried out for a time to obtain a copolymer. To 500 g of this copolymer, 12 g of acetic anhydride was added and reacted at 140 ° C. for 4 hours, and the produced acetic acid was removed under reduced pressure to obtain S-4. Molecular weight of S-4
The value was 17200, the hydroxyl value was 11, and the acid value was 0.8.

.. Production of R-1 By the same operation as that of S-1 (but without acetylation), polydimethylsiloxane modified with terminal bishydroxypropyl (molecular weight 8500 (70 g was reacted with 630 g ε-caprolactone). R-1 was obtained, which had a molecular weight of about 8500 and a hydroxyl value of 1.6.

.. Manufacture of R-2 By the same operation as in S-1 (but without acetylation), 630 g of terminal bishydroxypropyl-modified polydimethylsiloxane (molecular weight 8500) was reacted with 70 g of ε-caprolactone. R-2 was obtained. The molecular weight of R-2 was 9500 and the hydroxyl value was 12.0.

.. Production of R-3 By the same operation as that of S-1 (but without acetylation), 300 g of terminal hydroxybutyl polydimethylsiloxane (molecular weight 2300) is added to 30 g of ε-caprolactone.
0g was made to react and R-3 was obtained. R-3 molecular weight of about 4600,
The hydroxyl value was 24.3.

.. Production of R-4 By the same operation as in S-1, but without acetylation, 500 g of terminal hydroxymethylpolydimethylsiloxane (molecular weight 7400) was added to 50 g of ε-caprolactone.
R-4 was obtained by reacting 0 g. R-4 molecular weight approx. 1470
It was 0 and the hydroxyl value was 7.6.

.. Production of R-5 By the same operation as that for S-1 (but without acetylation), 300 g of terminal hydroxymethylpolydimethylsiloxane (molecular weight 7400) was added to 70 g of ε-caprolactone.
R-5 was obtained by reacting 0 g. R-5 molecular weight about 2440
It was 0 and the hydroxyl value was 4.6.

Production of R-6 150 g of ε-caprolactone, 150 g of terminal hydroxypolydimethylsiloxane (molecular weight 7200) and 0.3 g of tetraisopropyl titanate were charged in a reaction vessel and stirred. Warm the contents under stirring, raise the sound to 90 ° C over 1.5 hours, and raise the sound to 120 ° C over 0.5 hours, then 120-1
The reaction was carried out at 30 ° C for 3 hours. Then, unreacted ε-caprolactone was removed over 3 hours at a reduced pressure of 1 mmHg at this temperature to obtain R-6. R-6 had a molecular weight of about 12,000 and a hydroxyl value of 4.6.

-Test Category 2 (evaluation example as impact resistance improver) 100 parts by weight of polybutylene terephthalate for injection molding and polysiloxane / polyester copolymer as shown in Table 1 or other additives were tested. It was charged into a small kneading machine for kneading and kneaded at 250 ° C. for the time shown in Table 1. Then, using the kneaded product, with a hot press machine, a thickness of 2 m
m sheets were formed. At the same time, a sheet consisting of only the above polybutylene terephthalate was similarly formed (blank). The state during melt kneading and the impact resistance of each molded sheet were evaluated by the following methods, and the results are shown in Table 1.

.. Evaluation method (1) Kneading property The state during melt kneading was evaluated according to the following criteria.

○: No particular abnormality △: Slip phenomenon or increase in melt-kneaded product per year was observed ×: Slip phenomenon occurred remarkably or melt-kneaded product increased significantly in year and kneading was difficult (2) Appearance sheet Was visually observed, and the uniformity and the degree of coloring were evaluated according to the following criteria.

◯: It has a uniform and smooth surface, and the coloration is similar to that of the blank.

Δ: Slight surface stains and spots are observed and slightly colored compared to the blank X: Surface is uniform and stains and coloration are noticeable (3) Impact resistance Evaluation by the simple falling ball test method did. That is, the interval 10
A test was carried out at 23 ° C. and 10 ° C. in which a sheet was set horizontally on a support base of cm and a steel ball having a weight of 28.2 g and a diameter of 2 cm was naturally dropped from a height of 175 cm. The above-mentioned test was carried out for each of the five sheets, and the damage condition of those sheets was evaluated according to the following criteria. Separately, using 5 sheets each, 4 by an accelerated weathering tester (made by Q.Panel)
Each of the samples after irradiation for 00 hours was similarly tested at 23 ° C. to evaluate the damage condition.

⊚: No damage was observed on all 5 sheets. ○: Out of 5 sheets, slight damage such as cracks or depressions was observed within 2 sheets. ×: Among 5 sheets, Damage is observed on three or more sheets. (4) | Δη | (decreased molecular weight) For each melt-kneaded product, the limit year of the orthochlorophenol solution at 35 ° C was measured, and | Δη | It evaluated by the standard of.

| Δη | = | (η-η0) / η0 | × 100 [where η is the limit year of each melt-kneaded product, and η0 is the limit year of blank] ◎: | Δη | <2 (physical properties, moldability and resin Good flowability) ○: 2 ≦ | Δη | <4 (small deterioration of physical properties) ×: 4 ≦ | Δη | (large deterioration of physical properties) ・ Test Category 3 (evaluation example as impact resistance improver) 100 parts by weight of polyethylene terephthalate and polysiloxane / polyester copolymer as shown in Table 2 or other additives were put into a small experimental kneader. Preparation, 250
Kneading was carried out at 0 ° C for the time shown in Table 2. Then, using the kneaded product, hot press machine at a temperature of 250 ° C. for 4 hours
A plate having a thickness of 1.5 mm was formed at a pressure of min × pressure of 200 kg / cm ² . At the same time, the same plate made of polyethylene terephthalate was used as a blank (blank), and the state during melt-kneading and the impact resistance of each plate were evaluated in the same manner as in Test Category 2, and the results are shown in Table 2. Indicated.

<Effects of the Invention> As is clear from the results shown in Tables 1 and 2, the present invention described above has the effect that excellent impact resistance can be imparted without impairing the original polyester resin. There is.

Claims (4)

(57) [Claims] 1. A polysiloxane block having a molecular weight of 4000 to 70,000 in a molecule and a polyester block represented by the following formula 1 directly bonded to a silicon atom of the polysiloxane block, and the ratio of both is polysiloxane block / polyester. An impact resistance improver for a polyester resin, which comprises a polysiloxane / polyester copolymer having a block of 20 to 80/80 to 20 (each% by weight). [However, m is an integer of 1 to 6. n is an integer of 1 to 400.
a is an integer of 1 to 6. R ¹ is H or an alkyl group having 1 to 6 carbon atoms. R ² is an alkyl group having 1 to 18 carbon atoms, 1 carbon atom
~ 18 alkenyl group, benzyl group, or C2-18 acyl group. ] 2. The impact resistance improver for polyester resin according to claim 1, wherein the polyester block is a polyester block represented by the following formula 2. [However, n and R ² are the same as in Equation 1. ] 3. A polyester resin containing 0.2 to 7% by weight of the impact resistance improver for polyester resin according to claim 1 or 2.
A polyester resin composition formed by blending. 4. The polyester resin composition according to claim 3, wherein the polyester resin is polybutylene terephthalate and / or polyethylene terephthalate.