JP4160230B2 - Resin pellet mixture and method for producing molded product using the same - Google Patents

Description

【００４５】
［比較例１］
表１に記載の熱可塑性樹脂ペレットを所定の割合で均一にブレンドして樹脂ペレット混合物を得た。これを射出成形機に移送してハーネスコネクターを上記条件で成形した。100ショットの連続成形を行い、計量時間のばらつきを調べた。結果を表１に示す。
【００４６】
本発明の二つの結晶融解ピークを有するポリブチレンテレフタレートペレットを含まない、比較例の樹脂ペレット混合物では、計量時間のばらつきが大きいことがわかる。
【００４７】
【発明の効果】
本発明によれば、マスターバッチペレットを用い、良好な靭性を備えながらも、マスターペレット製造時の吐出安定性が良好で、射出成形により成形する際に計量時間のばらつきが少ない樹脂ペレット混合物を提供することができる。本発明によればハーネスコネクター用途に特に好適な靭性の改良された樹脂ペレット混合物を提供することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin pellet mixture. More particularly, the present invention relates to a resin pellet mixture useful for automobile parts such as a harness connector.
[0002]
[Prior art]
As a production method to obtain molded products with various functionalities while ensuring process flexibility, the functionality-imparting agent is dispersed in the thermoplastic resin at a high concentration several to several tens of times the specified blending ratio. Masterbatch is known.
[0003]
[Problems to be solved by the invention]
However, depending on the function-imparting agent, it is difficult to blend in a master batch at a high concentration, and the supply stability of the master batch and the dispersibility in a thermoplastic resin are generally not always satisfactory.
[0004]
For example, when a soft polymer is used as a function-imparting agent to improve toughness, the master batch pellets become sticky when blended with a high concentration of the soft polymer, and the pellets adhere to each other due to heat or dead weight and are molded. The supply of pellets becomes unstable, and the pellets slip and cannot be measured when plasticizing in the molding machine.
[0005]
Further, when a release agent is used as a function-imparting agent in order to improve the release property, if the release agent is blended at a high concentration, the master batch pellet slips and the bite of the pellet becomes unstable.
[0006]
The present invention aims to solve these problems, uses master batch pellets, has good toughness, but has good discharge stability during the production of master pellets, and metering time when molding by injection molding An object of the present invention is to provide a resin pellet mixture in which there is little variation. An object of the present invention is to provide a resin pellet mixture having improved toughness particularly suitable for harness connector applications.
[0007]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have found that the use of polybutylene terephthalate pellets having specific crystallinity as polybutylene terephthalate improves the stability of the supply of molding material and reduces the variation in measurement time. The invention has been reached.
[0008]
That is, the present invention
A polyester elastomer (A-1) 1~30wt% of masterbatch pellets were blended by melt kneading a functionality-imparting agent in polybutylene terephthalate (A), polybutylene terephthalate pellets and (B), (A) / (B) is a resin pellet mixture obtained by mixing so that the weight ratio is 2/98 to 50/50, and the polybutylene terephthalate pellet (B) has a temperature range of 200 to 220 ° C. and 220 to 230. It is a resin pellet mixture characterized by containing 10 to 100 wt% of the total amount of (B) polybutylene terephthalate pellets (B-1) each having one crystal melting peak in a temperature range of ° C.
The present invention is described in detail below.
[0009]
[Polybutylene terephthalate]
Polybutylene terephthalate is an aromatic polyester in which the acid component is terephthalic acid and the diol component is tetramethylene glycol, and a part thereof may be substituted with a copolymer component, such as isophthalic acid, Phthalic acid; alkyl-substituted phthalic acids such as methyl terephthalic acid and methyl isophthalic acid; naphthalene dicarboxylic acids such as 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid and 1,5-naphthalene dicarboxylic acid; 4,4 ′ -Diphenyl dicarboxylic acids such as diphenyldicarboxylic acid and 3,4'-diphenyldicarboxylic acid; aromatic dicarboxylic acids such as diphenoxyethanedicarboxylic acid such as 4,4'-diphenoxyethanedicarboxylic acid; succinic acid, adipic acid and sebatin Acid, azelaic acid, decanedicarboxylic acid, cyclohexanedicarbo Aliphatic or alicyclic dicarboxylic acids such as acids; Alicyclic diols such as 1,4-cyclohexanedimethanol; Dihydroxybenzenes such as hydroquinone and resorcin; 2,2′-bis (4-hydroxyphenyl) propane; Bisphenol compounds such as 2'-bis (4-hydroxyphenyl) sulfone; aromatic diols such as ether diols obtained from bisphenol compounds and glycols such as ethylene glycol; ε-oxycaproic acid, hydroxybenzoic acid, hydroxyethoxybenzoic acid And oxycarboxylic acids such as The copolymer component can be used in a proportion of preferably 30 mol% or less, more preferably 10 mol% or less of the total acid component or diol component.
[0010]
Furthermore, as a branching component to the above-mentioned aromatic polyester, an acid having a polyfunctional ester-forming ability such as trimesic acid or trimellitic acid or an alcohol having a polyfunctional ester-forming ability such as glycerin, trimethylolpropane, pentaerythritol, etc. Copolymerization may be carried out at a ratio of 1.0 mol% or less, preferably 0.5 mol% or less, more preferably 0.3 mol% or less.
[0011]
Polybutylene terephthalate preferably has an intrinsic viscosity of 0.4 to 1.2, more preferably 0.7 to 1.1. If it is less than 0.4, sufficient characteristics cannot be obtained, and if it exceeds 1.2, the melt viscosity is high, the fluidity is lowered, and the moldability is impaired. The intrinsic viscosity (same as the intrinsic viscosity) is measured at 25 ° C. using o-chlorophenol as a solvent.
[0012]
The polybutylene terephthalate is used as the polybutylene terephthalate of the master batch pellet (A) and the polybutylene terephthalate pellet (B).
[0013]
[Polybutylene terephthalate pellet (B)]
The polybutylene terephthalate pellet (B) is a polybutylene terephthalate pellet (B-1) having one crystal melting peak in each of a temperature range of 200 to 220 ° C and a temperature range of 220 to 230 ° C. Contains 100 wt%.
[0014]
Polybutylene terephthalate is known to form various spherulites depending on the crystallization conditions. For example, Polymer Engineering and Science, Vol. 3, P.I. No. 143 reports that two spherulites having a melting point of 225 ° C., a heat of fusion of 48 J / g and a melting point of 220 ° C. and a heat of fusion of 60 J / g are formed.
[0015]
The polybutylene terephthalate pellet (B-1) was obtained at 2 ° C./min. By DSC. It is the pellet of the crystallization state which has the melting peak of a crystal | crystallization in each temperature range of 200-220 degreeC and 220-230 degreeC, when it measures with the temperature increase rate of. On the other hand, polybutylene terephthalate pellets obtained by ordinary melt-kneading are pellets in a crystallized state showing a single crystal melting peak in a temperature range of 220 to 230 ° C.
[0016]
When the content of the polybutylene terephthalate pellets (B-1) in the polybutylene terephthalate pellets (B) is less than 10 wt%, the effect of stabilizing the measuring time when molding by injection molding cannot be obtained. Content wt% is a value based on the total amount of polybutylene terephthalate pellets (B).
[0017]
The polybutylene terephthalate pellet (B-1) can be obtained, for example, by performing an aging treatment at 180 to 225 ° C. for 2 to 24 hours under a normal pressure nitrogen atmosphere.
[0018]
[Master batch pellet (A)]
The master batch pellet (A) is preferably produced using polybutylene terephthalate pellets (A-5) each having one crystal melting peak in a temperature range of 200 to 220 ° C and a temperature range of 220 to 230 ° C. By using the polybutylene terephthalate pellet (A-5), the ejection stability during the production of the master pellet is improved.
[0019]
This polybutylene terephthalate pellet (A-5) is a pellet in the same crystallized state as the above-mentioned polybutylene terephthalate pellet (B-1), and is produced by the same method as the polybutylene terephthalate pellet (B-1). be able to.
[0020]
[Polyester elastomer]
The polyester elastomer (A-1) is a polyester block composed of an aromatic polyester block (A) having a crystallinity of a melting point of 200 ° C. or higher and a block (A) made of polyoxyalkylene glycol having a molecular weight of 500 or more. It is a copolymer.
[0021]
The aromatic polyester block (a) having crystallinity is composed of polybutylene terephthalate composed of terephthalic acid or an ester-forming derivative thereof and tetramethylene glycol or an ester-forming derivative thereof. A third component may be copolymerized with the polybutylene terephthalate. Examples of the third component include a dicarboxylic acid component and a diol component.
[0022]
Examples of the third component dicarboxylic acid component include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid and naphthalenedicarboxylic acid; aliphatic dicarboxylic acids such as adipic acid and sebacic acid; and alicyclic groups such as cyclohexanedicarboxylic acid. can do. These can be copolymerized within a range of 10 mol% or less, preferably 5 mol% or less, based on the total dicarboxylic acid component.
[0023]
Examples of the diol component of the third component include aliphatic glycols such as ethylene glycol and hexamethylene glycol; alicyclic diols such as cyclohexanedimethanol; aromatic diols such as bisphenol A and hydroquinone. These can be copolymerized within a range of 10 mol% or less, preferably 5 mol% or less, based on the total diol component. When the third component exceeds 10 mol%, the crystallinity of the polyester elastomer is lowered, and problems such as blocking and welding may occur, making handling difficult.
[0024]
Examples of the polyoxyalkylene glycol constituting the block (i) composed of a polyoxyalkylene glycol having a molecular weight of 500 or more include polyethylene glycol, polypropylene glycol and polytetramethylene glycol, preferably polytetramethylene glycol. is there. When polytetramethylene glycol is used, the molecular weight is preferably 500 to 4000, more preferably 800 to 4000. By using polytetramethylene glycol having a molecular weight within this range, good toughness and elongation can be obtained, and at the same time, sufficient compatibility with polybutylene terephthalate can be maintained.
[0025]
The weight ratio of the block (A) to the block (A) in the polyester elastomer is preferably from 95 to 20% by weight of the block (A) to 5 to 80% by weight of the block (A), more preferably from 80 to 30 of the block (A). % To block (b) 20-70% by weight.
[0026]
The polyester elastomer is compounded into master batch pellets. The amount of this case, the total weight with respect to 1 30 wt% of the resin composition of the masterbatch pellets, more preferably from 1 to 20 wt%. By blending in this range, pellets do not slip during molding, making it difficult to measure, and it is possible to obtain a resin composition having excellent molding workability and particularly excellent toughness.
[0027]
[Hindered phenolic antioxidants, phosphite antioxidants]
Hindered phenolic antioxidants (A-2) and phosphite antioxidants to suppress the deterioration of the resin during melt-kneading during the masterbatch production and maintain the heat-resistant deterioration characteristics of the molded products. It is preferable to use (A-3).
[0028]
The hindered phenolic antioxidant (A-2) is preferably 1, 1 in order to suppress the deterioration of the resin during melt kneading during the production of the masterbatch and to maintain the heat resistance deterioration characteristics of the molded article. 3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], penta Erythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N ′ Hexamethylene bis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di t-butyl-4-hydroxybenzyl) benzene, 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [ 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 3,9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy ] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate Yes, particularly preferably pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate].
[0029]
From the same viewpoint, the phosphite antioxidant (A-3) is preferably bis (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, Bisoctadecyl pentaerythritol diphosphite and bis (4-methyl-2,6-di-t-butylphenyl) pentaerythritol diphosphite, particularly preferably bis (2,4-di-t-butylphenyl) penta Erythritol diphosphite.
[0030]
The hindered phenol antioxidant (A-2) and the phosphite antioxidant (A-3) may be used alone or in combination of two or more.
[0031]
The hindered phenolic antioxidant (A-2) is preferably blended, and the blending amount in this case is 0.01 to 5 wt%, preferably 0.1 to 3 wt% of the total weight of the master batch pellet (A). The total weight of the resin pellet mixture for connectors is preferably 0.01 to 2 wt%, more preferably 0.02 to 1 wt%.
[0032]
The phosphite antioxidant (A-3) is preferably blended, and the blending amount in that case is 0.01 to 5 wt% of the total weight of the master batch pellet (A), preferably 0.1 to 3 wt%, The total weight of the resin pellet mixture for connectors is preferably 0.01 to 2 wt%, more preferably 0.02 to 1 wt%.
[0033]
[Release agent]
As the release agent (A-4), higher fatty acid, its ester or metal salt, and polyethylene wax can be used.
[0034]
As the higher fatty acid, fatty acids having 16 to 32 carbon atoms such as palmitic acid, stearic acid, behenic acid, and montanic acid can be preferably used.
[0035]
Suitable mold release agents are palmitic acid, stearic acid, behenic acid, montanic acid, glycerin monostearate, pentaerythritol monostearate, montanic acid ester, calcium stearate, sodium montanate, montanic acid partially saponified ester, high density type Polyethylene wax, maleic acid-modified polyethylene wax, and oxidized type polyethylene wax. Montanic acid esters are particularly preferred. One type of release agent may be used, or two or more types may be used.
[0036]
The release agent is preferably blended into the master batch pellet. The blending amount in this case is preferably 0.1 to 5 wt%, more preferably 0.1 to 3 wt%, based on the total weight of the resin composition of the master batch pellet. By mix | blending in this range, favorable measurement stability and favorable mold release property can be obtained.
[0037]
[Combination ratio]
In the present invention, by using a resin pellet mixture obtained by mixing a master batch pellet (A) and a polybutylene terephthalate pellet (B), which are blended by melting and kneading a functional imparting agent at a high concentration in polybutylene terephthalate. Manufacture molded products.
[0038]
The master batch pellet (A) and the polybutylene terephthalate pellet (B) are blended so that the weight ratio of (A) / (B) is 2/98 to 50/50. If the weight ratio of (A) / (B) is less than 2/98, it is difficult to uniformly disperse the compounding components in the masterbatch only by the plasticizing process at the time of molding. The economic effect is not obtained.
[0039]
The content of the polyester elastomer (A-1) in the resin pellet mixture is preferably 0.5 to 5 wt%. In an application such as an automobile part such as a harness connector, rigidity is required in order to ensure the male-female fitting of the connector together with the toughness of the hinge portion. By setting the content of the polyester elastomer (A-1) to 0.5 to 5 wt%, the rigidity of the connector can be ensured together with the toughness of the hinge portion to ensure male and female fitting of the connector.
[0040]
[Additive]
In the resin pellet mixture of the present invention, fibrous reinforcing materials such as glass fibers and carbon fibers, granular fillers such as glass fibers and carbon fibers, inorganic fillers such as granular, amorphous, plate-like, and the like, Additives such as nucleating agents, lubricants, antioxidants, UV absorbers, light stabilizers, heat stabilizers, antistatic agents, pigments, and other modifiers such as flame retardants, impact modifiers, fluidity improvers, etc. Can be included.
[0041]
These additives may be blended in the master batch pellet (A), may be blended in the polybutylene terephthalate pellet (B), or may be blended in both. And you may mix | blend at the time of mixing a masterbatch pellet (A) and a polybutylene terephthalate (B).
[0042]
【Example】
EXAMPLES Hereinafter, an Example is given and this invention is explained in full detail. In addition, the part in an Example means a weight part.
The characteristics of the molded product were measured by molding a test piece under the following molding conditions.
Molding machine: Mitsubishi 80MSP-5C,
Cylinder temperature (℃): 240/245/250/255,
Mold temperature (℃): 30
[0043]
[Example 1]
The thermoplastic resin pellets shown in Table 1 were uniformly blended at a predetermined ratio to obtain a resin pellet mixture. This was transferred to an injection molding machine and a harness connector was molded under the above conditions. 100 shots of continuous molding were performed, and the variation in weighing time was examined. The results are shown in Table 1.
It can be seen that the resin pellet mixture of the present invention has good moldability with little variation in measurement time.
[0044]
[Table 1]

[0045]
[Comparative Example 1]
The thermoplastic resin pellets shown in Table 1 were uniformly blended at a predetermined ratio to obtain a resin pellet mixture. This was transferred to an injection molding machine and a harness connector was molded under the above conditions. 100 shots of continuous molding were performed, and the variation in weighing time was examined. The results are shown in Table 1.
[0046]
It can be seen that the resin pellet mixture of the comparative example, which does not include the polybutylene terephthalate pellets having two crystal melting peaks of the present invention, has a large variation in measurement time.
[0047]
【The invention's effect】
According to the present invention, it is possible to provide a resin pellet mixture that uses master batch pellets and has good toughness but also has good discharge stability during production of master pellets and little variation in measurement time when molding by injection molding. can do. ADVANTAGE OF THE INVENTION According to this invention, the resin pellet mixture with improved toughness especially suitable for harness connector use can be provided.

Claims (4)

A polyester elastomer (A-1) 1~30wt% of masterbatch pellets were blended by melt kneading a functionality-imparting agent in polybutylene terephthalate (A), polybutylene terephthalate pellets and (B), (A) / (B) is a resin pellet mixture obtained by mixing so that the weight ratio is 2/98 to 50/50, and the polybutylene terephthalate pellet (B) has a temperature range of 200 to 220 ° C. and 220 to 230. A resin pellet mixture comprising 10 to 100 wt% of the total amount of (B) polybutylene terephthalate pellets (B-1) each having a crystal melting peak in a temperature range of ° C.   Master batch pellet (A) is polyester elastomer (A-1) 1-30 wt%, hindered phenolic antioxidant (A-2) 0.01-5 wt%, phosphite antioxidant (A-3) The resin pellet mixture of Claim 1 formed by mix | blending 0.01-5 wt% and mold release agent (A-4) 0.1-5 wt% with polybutylene terephthalate.   Master batch pellets (A) produced using polybutylene terephthalate pellets (A-5) each having one crystal melting peak in a temperature range of 200 to 220 ° C and a temperature range of 220 to 230 ° C The resin pellet mixture according to claim 1, which is (A). Polyester elastomer as functionality-imparting agent in polybutylene terephthalate (A-1) 1~30wt% of masterbatch pellets were blended by melt kneading (A) and polybutylene terephthalate pellets (B) obtained by mixing a resin In the manufacturing method of the molded article using a pellet mixture, The manufacturing method of the molded article using the resin pellet mixture in any one of Claims 1 thru | or 3.