WO2018008748A1 - Composite resin molding production method - Google Patents

Abstract

The present invention provides a composite resin molding for which the strength when a resin molding is bonded to another molding can be further increased without restrictions on the presence or absence of inorganic fillers and on the color of the resin molding. This production method comprises an injection step ((B) in figure 1) for injecting a thermoplastic or thermosetting second resin composition on a non-flat surface 11 of a first resin molding that is made of a cured product of a thermoplastic first resin composition and has depressions and protrusions on the surface. The difference between the temperature of the second resin composition in the injection step and the Vicat softening point of the first resin molding 10 is 15°C to 300°C. Moreover, in the composite resin molding 1, when the height of the protrusions 13 of the first resin molding 10 is L (mm), the width of the protrusions 13 in a direction parallel to the direction in which the second resin composition is injected is d (mm), and the width in the direction perpendicular to the direction in which the second resin composition is injected is b (mm), the value of 6L/bd² is 5-600.

Description

Manufacturing method of resin composite molded body

The present invention relates to a method for producing a resin composite molded body.

In recent years, in fields such as automobiles, electrical products, industrial equipment, etc., there has been an increasing movement to replace metal moldings with resin moldings in order to meet demands for reducing carbon dioxide emissions and manufacturing costs. Accordingly, it is required to provide a technique for firmly integrating one resin molded body with another resin molded body.

Patent Document 1 discloses a method of manufacturing a composite molded product by integrating one resin molded body with another molded body. In this method, a resin molded product containing a fibrous inorganic filler is partially removed to form a groove in which the inorganic filler is exposed from the side surface to obtain a grooved resin molded article. The surface having the groove of the resin molded body is integrated with another molded body as a contact surface. When obtaining a grooved resin molded body, the resin is partially removed by laser irradiation. According to this method, the inorganic filler exposed in the groove serves as an anchor that suppresses the destruction of the grooved resin molded body and other molded bodies, and as a result, the strength of the composite molded body can be significantly increased.

Patent Document 2 discloses an insert molding method in which a resin molded part is inserted into a mold, a resin is injection molded around the resin molded part, and integrated with the resin molded part. In this method, either a specific resin A (polyacetal resin, polyamide resin or polypropylene resin) or a specific resin B (styrene resin such as ABS resin or polycarbonate resin) is used as a molding material for a resin molded part to be inserted into a mold. One is used, and the other of the specific resins A and B is used as a resin for injection molding. Then, protrusions such as ribs remaining inside the injection-molded resin are formed by being deformed by the resin injected at the time of insert molding or outsert molding at an appropriate position of the resin molded part to be inserted into the mold. According to this method, since protrusions such as ribs formed in advance on the resin molded part to be inserted into the mold are deformed by injection molding and remain inside the injection molded resin, the resins that are not fused to each other are in contact with each other. Even when peeled off, the deformed protrusions such as ribs connect the molded parts to each other like a wedge, and the resin molded part on one side can be prevented from falling off.

Japanese Patent No. 5632567 JP-A-7-137089

However, in the technique described in Patent Document 1, since the inorganic filler exposed in the groove is used as an anchor, at least one resin molded body must contain the inorganic filler. Therefore, even if neither of the two types of resin molded bodies constituting the resin composite molded body contains an inorganic filler, it is required to provide a technique capable of firmly bonding the two.

Further, in the technique described in Patent Document 1, since the resin is partially removed from the resin molded product containing the fibrous inorganic filler by laser irradiation, the color of the resin molded product is high in laser absorption. It needs to be colored. Therefore, in the technique described in Patent Document 1, there is a restriction on the color of the resin molded product containing the fibrous inorganic filler.

Further, in the method described in Patent Document 2, there is still room for improvement in the bonding strength at the bonding interface.

The present invention has been made in order to solve the above-described problems, and the purpose of the present invention is to provide another molded body without any restrictions on the presence or absence of an inorganic filler in the resin molded body and the color of the resin molded body. It is an object of the present invention to provide a resin composite molded body capable of further increasing the strength when bonded to.

The inventors of the present invention have intensively studied to solve the above problems. As a result, the injection temperature when injecting the second resin composition on the surface of the first resin molded body is within a predetermined range, and the shape of the surface of the first resin molded body is set to a predetermined shape, The present inventors have found that the above problems can be solved and have completed the present invention. Specifically, the present invention provides the following.

(1) The present invention consists of a cured product of a thermoplastic first resin composition, and injects a thermoplastic or thermosetting second resin composition onto the surface of a first resin molded body having irregularities on the surface. A method for producing a resin composite molded body in which the first resin molded body and a second resin molded body made of a cured product of the second resin composition are joined, each including an injection process, The difference between the temperature of the second resin composition and the Vicat softening point of the first resin molded body is 15 ° C. or higher and 300 ° C. or lower. In the resin composite molded body, the unevenness of the first resin molded body is The height of the convex portion is L (mm), the width of the convex portion, and the width in the direction parallel to the direction in which the second resin composition is injected is d (mm), and the second resin composition is When the width in the direction perpendicular to the injected direction is b (mm), the value of 6 L / bd ² is 5 or less. It is the manufacturing method of the resin composite molded object which is 600 or less.

(2) Moreover, this invention is the manufacturing method of the resin compound molded object as described in (1) whose resin which comprises the said 1st resin composition, and resin which comprises the said 2nd resin composition are the same. It is.

According to the present invention, there is provided a resin composite molded body capable of further increasing the strength when bonded to another molded body without any restrictions on the presence or absence of an inorganic filler in the resin molded body and the color of the resin molded body. Can be provided.

It is a schematic diagram which shows an example of the manufacturing method of the resin compound molded object 1 which concerns on this embodiment. It is a schematic diagram which shows the state of the uneven surface 11 of the 1st resin molded object 10 in the resin composite molded object 1. FIG. It is a figure which shows the modification of the uneven surface 11. FIG. It is a schematic diagram for demonstrating the difficulty of falling down of the convex part 13 of the uneven | corrugated surface 11 when the 2nd resin composition is inject | poured on the uneven | corrugated surface 11 of the 1st resin molding 10 with the injection pressure P (N). It is a figure which shows the measurement result of the fracture load in Test Example 2. It is a figure which shows the measurement result of the fracture load in Test Example 3. FIG. 4 is a view showing a cross section when cut so that the boundary between the first resin molded body 10 and the second resin molded body 20 can be observed from the upper side to the lower side of the resin composite molded body 1 according to Test Example 1-3. .

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention. . In addition, although description may be abbreviate | omitted suitably about the location where description overlaps, the summary of invention is not limited.

<Method for producing resin composite molded body>
FIG. 1 is a schematic diagram showing an example of the manufacturing method of the present embodiment.

In the manufacturing method according to the present embodiment, first, as shown in FIG. 1A, the first resin composition (primary resin) is firstly treated using an injection mold having irregularities formed on the molding surface. It shape | molds and the 1st resin molding 10 which has the uneven | corrugated surface 11 whose surface is uneven | corrugated shape is obtained (primary shaping | molding process).

Subsequently, as shown in FIG. 1B, the first resin molded body 10 is put into a mold (not shown), and an uncured second resin is formed inside the mold with the uneven surface 11 as a contact surface. 2 Resin composition is injected (injection process). Then, the second resin composition is cured, and the first resin molded body 10 and the second resin molded body 20 made of a cured product of the second resin composition are integrated to obtain the resin composite molded body 1.

[Primary molding process]
[First resin composition]
The resin constituting the first resin composition is not particularly limited as long as it is thermoplastic. Examples of suitable resins include polyacetal (POM), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), liquid crystal polymer (LCP), and the like.

[Injection mold]
Although illustration is omitted, unevenness is formed on the molding surface of the injection mold, and the shape can be transferred to the object of injection molding.

[First resin molded body 10]
2A is a schematic diagram illustrating a state of the uneven surface 11 of the first resin molded body 10, and FIG. 2B is a partially enlarged view of the uneven surface 11. The uneven surface 11 includes a concave portion 12 (corresponding to “groove”) and a convex portion 13 (corresponding to “mountain”).

By forming a plurality of concave portions 12 and convex portions 13 alternately, the first resin molded body 10 and the second resin molded body 20 can be joined more firmly.

In FIG. 2, the uneven surface 11 is described as having a mesh shape (a shape in which the convex portions 13 are formed in a mesh shape), but the shape of the uneven surface 11 is not particularly limited. For example, as shown in FIG. 3A, the shape of the concavo-convex surface 11 may be a striped shape (a shape in which the concave portions 12 and the convex portions 13 are alternately formed in a striped shape). As shown in (B), the shape of the concavo-convex surface 11 may be a contour line (a shape in which the concave portions 12 and the convex portions 13 are alternately formed in contour lines). Further, as shown in FIG. 3C, the shape of the uneven surface 11 may be an oblique lattice shape (a shape in which the convex portions 13 are arranged obliquely with respect to the sides of the uneven surface 11). Especially, it is preferable that the shape of the uneven | corrugated surface 11 is mesh shape at the point which can join the 1st resin molded object 10 and the 2nd resin molded object 20 still more firmly.

Although not shown, the shape of the convex portion 13 is not limited to a quadrangle, and may be a round shape or an oval shape.

When the height of the convex portion 13 of the first resin molded body 10 is L (mm), the width in the first direction of the convex portion 13 is d (mm), and the width in the second direction is b (mm), 6L The value of / bd ² is 600 or less. Here, the first direction refers to a direction parallel to the direction in which the second resin composition is injected, and the second direction refers to a direction perpendicular to the direction in which the second resin composition is injected.

FIG. 4 is a schematic view for explaining the difficulty of falling down the convex portion 13 of the concave and convex surface 11 when the second resin composition is injected onto the concave and convex surface 11 of the first resin molded body 10 at the injection pressure P (N). FIG. The difficulty of falling down the convex portion 13 can be expressed by a bending stress σ _b (MPa), and the bending stress σ _b is expressed by 6LP / bd ² . In the present embodiment, 6L / bd ² is a coefficient a, and the difficulty of falling down the convex portion 13 is evaluated based on the magnitude of the coefficient a.

The upper limit of the coefficient a (6L / bd ² ) may be 600 or less, preferably 400 or less, more preferably 200 or less, and even more preferably 100 or less. If the coefficient a is too large, when the second resin composition is injected onto the concavo-convex surface 11 of the first resin molded body 10, the convex portion 13 falls down, and the concavo-convex surface 11 forms the first resin molded body 10 and the second resin molded body. There is a possibility that the role of the anchor that suppresses the destruction of the body 20 cannot be sufficiently fulfilled.

In addition, an increase in the coefficient a of the convex portion 13 of the molded product means that the convex portion 13 has an elongated shape, and an elongated concave structure corresponding to the convex portion 13 is provided on the mold side for molding the convex portion 13. Therefore, when the coefficient “a” is extremely large, the degree of difficulty may increase from the viewpoint of mold manufacture.

The lower limit of the coefficient a (6L / bd ² ) may be 5 or more, preferably 10 or more, and more preferably 20 or more. If the coefficient a is too small, the uneven surface 11 may not sufficiently perform the function of an anchor that suppresses the destruction of the first resin molded body 10 and the second resin molded body 20.

The interval (pitch) P between the adjacent convex portions 13 is not particularly limited, but P is the width (groove width) of the concave portion 12 in order to firmly join the first resin molded body 10 and the second resin molded body 20. If W is 1.5 to 4 times W, that is, the groove width is 0.2 mm, it is preferably 0.3 mm to 0.8 mm, and it is preferably 2 to 3 times W, that is, the groove width. If it is 0.2 mm, it is more preferable that it is 0.4 mm or more and 0.6 mm or less. If the interval (pitch) P between the adjacent convex portions 13 is too narrow, the width (b, d) of the convex portion 13 and the groove width W are both narrow, so that the structural strength of the convex portion 13 of the first resin molded body 10 is reduced. Since the structural strength of the portion of the second resin molded body 20 that has entered the recess 12 of the first resin molded body 10 is low, the resin composite molded body 1 may be broken by a low external force.

Moreover, even if the space | interval (pitch) P of the adjacent convex part 13 is wide, if the groove width W is too narrow, it will be possible to destroy the 2nd resin molded object 20 with a low external force by applying external force to the resin composite molded object 1. Similarly, even if the interval (pitch) P between the adjacent convex portions 13 is wide, if the width (b, d) of the convex portions 13 is too narrow, an external force is applied to the resin composite molded body 1, so that the first There is a possibility that the resin molded body 10 is broken by a low external force.

[Injection process]
The injection step is a step of placing the first resin molded body 10 in a mold (not shown) and injecting an uncured second resin composition into the mold using the uneven surface 11 as a contact surface. .

[Second resin composition]
The resin constituting the second resin composition is thermoplastic or thermosetting. In addition, if the melting point of the second resin composition is equal to or higher than the melting point of the first resin composition, the temperature when injecting the second resin composition is usually higher than the thermal deformation temperature of the first resin composition. Because of this tendency, it becomes easy to obtain the caulking effect described later, but even if the melting point of the second resin composition is equal to or lower than the melting point of the first resin composition, the temperature is higher than the thermal deformation temperature of the first resin composition. Any combination that can inject the second resin composition is applicable in the present invention.

When the melting point of the second resin composition is lower than the melting point of the first resin composition, when the uncured second resin composition is injected onto the uneven surface 11 of the first resin molded body 10, the first resin is injected. Since the uneven surface 11 of the molded body 10 tends not to be thermally deformed, it is preferable to increase the shape factor a. The range of the shape factor a is preferably 100 or more, more preferably 200 or more and 500 or less.

The resin constituting the first resin composition and the resin constituting the second resin composition may be the same or different. Among them, the technique described in Patent Document 1 (partially removing a resin from a resin molded product containing a fibrous inorganic filler, forming a groove in which the inorganic filler is exposed from the side surface, and forming a grooved resin molded body. After obtaining, compared to the method of integrating the grooved resin molded body with other molded bodies using the grooved surface as a contact surface, a high strength resin composite molded body 1 is obtained, so the first resin composition The resin constituting the product and the resin constituting the second resin composition are preferably the same.

[Injection of second resin composition]
In injecting the second resin composition, the uncured second resin composition is disposed on the uneven surface of the first resin molded body 10 at a temperature equal to or higher than the thermal deformation temperature (Vicat softening point) of the first resin molded body 10. To do. Thereby, a part of the uneven surface 11 of the first resin molded body 10 is thermally deformed, and the contact surface of the second resin molded body 20 with the first resin molded body 10 is uneven on the surface of the first resin molded body 10. Can be caulked by.

The difference (ΔT) between the temperature of the second resin composition in the injection step and the Vicat softening point of the first resin molded body is 15 ° C. or more and 300 ° C. or less, more preferably 30 ° C. or more and 110 ° C. or less. It is more preferably 40 ° C. or higher and 90 ° C. or lower, still more preferably 45 ° C. or higher and 80 ° C. or lower, and particularly preferably 50 ° C. or higher and 70 ° C. or lower.

If the ΔT is too small, the uneven surface 11 of the first resin molded body 10 cannot be sufficiently thermally deformed, and as a result, the first resin molded body 10 and the second resin molded body 20 cannot be suitably joined. This is not preferable because of its properties.

On the other hand, if ΔT is too large, the uneven surface 11 of the first resin molded body 10 is dissolved, and the convex portion 13 of the uneven surface 11 may be lost.

The injection pressure is such that the second resin composition enters the recess (groove) 12 of the first resin molded body 10 and the uneven surface 11 of the first resin molded body 10 can exhibit the anchor effect and the holding pressure after filling. If it is.

The injection speed is an injection speed at which the uncured second resin composition enters the concave portion 12 during injection press-fitting, applies stress to a part of the convex portion 13, and deforms and caulks the convex portion 13. If it is.

[Curing process]
In the curing step, the uncured second resin composition supplied in the injection step is cured, and the first resin molded body 10 and the second resin molded body 20 made of a cured product of the second resin composition are integrated. This is a step of obtaining the resin composite molded body 1. By undergoing the primary molding step, the injection step, and the curing step, the resin composite molded body 1 by multiple molding is obtained.

[Evaluation of resin composite molded body 1]
As described above, the value of the coefficient a (6L / bd ² ) for the first resin molded body 10 is 5 or more and 600 or less. In examining whether the technical scope of the present invention belongs, the coefficient a is evaluated from the resin composite molded body 1.

As a method for evaluating the coefficient a from the resin composite molded body 1, (1) Evaluation by X-ray CT, (2) A solvent that dissolves the second resin molded body 20 without dissolving the first resin molded body 10 is used. Method of melting the second resin molded body 20 and evaluating the coefficient a for the remaining first resin molded body 10 (3) so that the boundary between the first resin molded body 10 and the second resin molded body 20 can be observed Examples include a method of cutting the resin composite molded body 1 and observing the boundary between the first resin molded body 10 and the second resin molded body 20 from the cross section after cutting. In this embodiment, since the coefficient a can be evaluated easily and at low cost, the resin composite molded body 1 is cut so that the boundary between the (3) first resin molded body 10 and the second resin molded body 20 can be observed. The coefficient a is evaluated by a method of observing the boundary between the first resin molded body 10 and the second resin molded body 20 from the cross section after cutting.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

<Test Example 1> Conditions of the primary molding process (shape of the uneven surface 11)
[Primary molding]
A polyphenylene sulfide resin (product name: Durafide 0220A9, Vicat softening point: 250 ° C., manufactured by Polyplastics Co., Ltd.) is injection-molded under the following conditions, and is a plate-shaped first having a length of 13 mm, a width of 65 mm, and a thickness of 6.5 mm. A resin molded body 10 was obtained.

Irregularities are formed on one side surface (vertical 6.5 mm, horizontal 13 mm) formed by the thickness direction and the vertical direction of the first resin molded body 10. The shape of the protrusion 13 on the uneven surface 11 made of this unevenness is as shown in Table 1, and each of the recesses has a width of 0.2 mm.
(Primary molding conditions)
Pre-drying: 140 ° C, 3 hours Cylinder temperature: 320 ° C
Mold temperature: 150 ° C
Injection speed: 20mm / sec
Holding pressure: 50 MPa

[Secondary molding]
Inserted into an injection mold having a cavity with a height of 13 m, a width of 130 mm, and a thickness of 6.5 mm using the uneven surface 11 of the first resin molded body 10 as a contact surface, and the same resin used for the primary molding The resin was injection molded under the same conditions as in the primary molding to obtain a resin composite molded body 1.

[Evaluation]
The bonding strength was measured for each of the resin composite molded bodies 1 according to Test Examples 1-1 to 1-5. The bonding strength was measured by pulling off the resin composite molded body 1 and measuring the breaking load. Tensilon UTA-50kN (Orientec Co., Ltd.) was used as a measuring instrument, and the crosshead speed was 10 mm / min. The results are shown in Table 1.

From Test Example 1, when the value of the coefficient a (6 L / bd ² ) is in the range of 5 or more and 600 or less, the uneven surface 11 of the first resin molded body 10 is integrated with the second resin molded body 20 as a contact surface. Thus, when the resin composite molded body 1 was obtained, it was confirmed that it was possible to significantly prevent the first resin molded body 10 and the second resin molded body 20 from being destroyed.

<Test Example 2> Comparison of conditions of secondary molding process (injection temperature of second resin composition) and resin material

In Table 2, the materials of the first resin composition and the second resin composition are as follows.
POM: Polyacetal resin (Product name: Duracon M90-44, Vicat softening point: 148 ° C, manufactured by Polyplastics)
POM with glass fiber: Polyacetal resin with glass fiber (Product name: Duracon GH-25, Vicat softening point: 154 ° C, manufactured by Polyplastics)
PBT: Polybutylene terephthalate resin (Product name: DURANEX 2200, Vicat softening point: 190 ° C, manufactured by Polyplastics)
Glass fiber-containing PBT: Polybutylene terephthalate resin containing glass fiber (Product name: DURANEX 3300, Vicat softening point: 214 ° C., manufactured by Polyplastics)
PPS: Polyphenylene sulfide resin (Product name: Durafide PPS 0220A9, Vicat softening point: 250 ° C., manufactured by Polyplastics)
PPS with glass fiber: Polyphenylene sulfide resin with glass fiber (Product name: Durafide PPS 1140A1, Vicat softening point: 266 ° C., manufactured by Polyplastics)
PEEK with glass fiber: Polyetheretherketone resin with glass fiber (Product name: VESTAKEEEP 2000GF30, manufactured by Daicel Evonik)

[Invention described in this embodiment]
First, the resin composite molded body 1 was obtained by the method described in this embodiment.
[Primary molding]
The first resin composition shown in Table 2 was injection-molded under the following conditions to obtain a first resin molded body 10 having the same shape as that of Test Example 1-2 (coefficient a (6L / bd ² ) = 38). .

(Conditions for injection molding in POM and POM with glass fiber)
Pre-drying: 80 ° C, 3 hours Cylinder temperature: 200 ° C
Mold temperature: 80 ℃
Injection speed: 16mm / sec
Holding pressure: 50 MPa

(Conditions for injection molding in PBT and PBT with glass fiber)
Pre-drying: 140 ° C, 3 hours Cylinder temperature: 260 ° C
Mold temperature: 60 ℃
Injection speed: 20mm / sec
Holding pressure: 50 MPa

(Conditions for injection molding in PPS and PPS with glass fiber)
Pre-drying: 140 ° C, 3 hours Cylinder temperature: 320 ° C
Mold temperature: 150 ° C
Injection speed: 20mm / sec
Holding pressure: 50 MPa

[Secondary molding]
Using the uneven surface 11 of the first resin molded body 10 as a contact surface, it is inserted into the same injection mold as in Test Example 1, the second resin composition shown in Table 2 is injection molded, and the resin composite molded body 1 Got. As shown in Table 2, a plurality of differences between the temperature of the second resin composition (cylinder temperature) and the Vicat softening point of the first resin molded body 10 were set within a range of −66 ° C. to 252 ° C. The conditions for injection molding differed depending on the type of resin constituting the second resin composition, similar to the conditions for primary molding.
In addition, the conditions of injection molding in glass fiber-containing PEEK are as follows.
(Conditions for injection molding in PEEK with glass fiber)
Pre-drying: 140 ° C, 3 hours Cylinder temperature: 400 ° C
Mold temperature: 180 ° C
Injection speed: 20mm / sec
Holding pressure: 80 MPa

[Evaluation]
For each of the resin composite molded bodies 1 according to Test Example 2, the bonding strength was measured by the same method as in Test Example 1. The results are shown in Table 2 and FIG.

From the result of Test Example 2 shown in FIG. 5, the difference (ΔT) between the temperature of the second resin composition and the Vicat softening point of the first resin molded body 10 when the second resin composition is injected is 15 ° C. or more and 300 When the temperature is equal to or lower than 1 ° C., when the uneven surface 11 of the first resin molded body 10 is integrated with the second resin molded body 20 as the contact surface to obtain the resin composite molded body 1, a bonding strength of 10 MPa or more is obtained. It can be said that the destruction of the first resin molded body 10 and the second resin molded body 20 can be significantly prevented.

From the results of Test Example 2, when the ΔT is 30 ° C. or higher and 110 ° C. or lower, a bonding strength of 20 MPa or higher is obtained. When the ΔT is 40 ° C. or more and 90 ° C. or less, a bonding strength of 30 MPa or more can be obtained. When the ΔT is 45 ° C. or more and 80 ° C. or less, a bonding strength of 40 MPa or more can be obtained. When the ΔT is 50 ° C. or more and 70 ° C. or less, a bonding strength of 50 MPa or more can be obtained.

If the above ΔT is less than 15 ° C., sufficient bonding strength cannot be obtained even if the resin composite molded body 1 is obtained. This is because the uneven surface 11 of the first resin molded body 10 cannot be sufficiently thermally deformed by the injection of the second resin composition, and as a result, the first resin molded body 10 and the second resin molded body 20 are suitable. This is presumably because the material could not be joined to the surface.

On the other hand, if ΔT exceeds 300 ° C., it is difficult to obtain sufficient bonding strength. This is presumably because the uneven surface 11 of the first resin molded body 10 is dissolved and the convex portion 13 of the uneven surface 11 tends to disappear.

(Test Examples 2-1 to 2-9) First resin composition = no glass fiber In Test Examples 2-1 to 2-9, the first resin molded body 10 does not contain glass fiber. The resin composite molded bodies 1 of Test Examples 2-1 to 2-9 all have a bonding strength of 10 MPa or more.

From Test Examples 2-1 to 2-9, according to the invention described in this embodiment, when the resin molded body is joined to another molded body without any restrictions on the presence or absence of an inorganic filler and the color of the resin molded body It is supported that a resin composite molded body capable of further increasing the strength of the resin can be provided.

Among them, in Test Examples 2-1, 2-2, 2-5, 2-8 and 2-9, the resin constituting the first resin composition and the resin constituting the second resin composition are the same. . The resin composite molded bodies 1 of Test Examples 2-1, 2-2, 2-5, 2-8, and 2-9 all have a bonding strength of 20 MPa or more.

From Test Examples 2-1, 2-2, 2-5, 2-8, and 2-9, in the invention described in the present embodiment, the resin constituting the first resin composition and the second resin composition are constituted. It is confirmed that the resin to be used is preferably the same.

(Test Examples 2-10 to 2-13) Resin constituting the first resin composition = resin constituting the second resin composition In Test Examples 2-10 to 2-13, the first resin molded body 10 was made of glass fiber. Containing. The resin constituting the first resin composition and the resin constituting the second resin composition are the same. The resin composite molded bodies 1 of Test Examples 2-10 to 2-13 all have a bonding strength of 20 MPa or more.

Also from Test Examples 2-10 to 2-13, in the invention described in this embodiment, the resin constituting the first resin composition and the resin constituting the second resin composition are preferably the same. That is supported.

(Test Examples 2-14 to 2-16) Difference between secondary molding cylinder temperature and Vicat softening point of first resin composition (ΔT) ≧ 15 ° C.
In Test Examples 2-14 to 2-16, the first resin molded body 10 contains glass fibers. And the resin which comprises the 1st resin composition differs from the resin which comprises the 2nd resin composition, and the temperature of the injection process of the 2nd resin composition is 15 from the Vicat softening point of the 1st resin composition. More than ℃.

The resin composite molded bodies 1 of Test Examples 2-14 to 2-16 all have a bonding strength of 10 MPa or more.

(Test Examples 2-17 to 2-25) Difference between secondary molding cylinder temperature and Vicat softening point of first resin composition (ΔT) <15 ° C.
In Test Examples 2-17 to 2-25, the first resin molded body 10 contains glass fibers. The resin constituting the first resin composition is different from the resin constituting the second resin composition, and the difference between the temperature of the injection process of the second resin composition and the Vicat softening point of the first resin composition Is lower than 15 ° C.

In this case, even when the uncured second resin composition is injected onto the uneven surface 11 of the first resin molded body 10, the uneven surface 11 of the first resin molded body 10 is not thermally deformed, and the first resin molding is performed. The body 10 and the second resin molded body 20 cannot be suitably joined. Therefore, the temperature of the injection process of the second resin composition needs to be 15 ° C. or more higher than the Vicat softening point of the first resin composition.

(Test Example 2-26)
In this example, the first resin composition is POM without glass fibers, and the second resin composition is PEEK with glass fibers. ΔT = 252 and the bonding strength was 10.2 MPa.

<Test Example 3> Invention described in Patent Document 1

In Table 3, the materials of the first resin composition and the second resin composition are as follows.
POM: Polyacetal resin (Product name: Duracon M90-44, Vicat softening point: 148 ° C, manufactured by Polyplastics)
POM with glass fiber: Polyacetal resin with glass fiber (Product name: Duracon GH-25, Vicat softening point: 154 ° C, manufactured by Polyplastics)
Glass fiber-containing PBT: Polybutylene terephthalate resin containing glass fiber (Product name: DURANEX 3300, Vicat softening point: 214 ° C., manufactured by Polyplastics)
PPS with glass fiber: Polyphenylene sulfide resin with glass fiber (Product name: Durafide PPS 1140A1, Vicat softening point: 266 ° C., manufactured by Polyplastics)

[Invention described in Patent Document 1]
As a control with Test Example 2, a resin composite molded body 1 was obtained by the method described in Patent Document 1.
[Manufacture of resin molded products with grooves]
The first resin composition described in Table 3 was injection molded under the following conditions to obtain a plate-like injection molded body having a length of 13 mm, a width of 65 mm, and a thickness of 6.5 mm, and then the thickness of the injection molded body. One side surface (length 6.5 mm, width 13 mm) formed by a direction and a lengthwise direction was irradiated with a laser 30 times in a diagonal lattice so that the groove width was 100 μm and the distance between adjacent grooves was 300 μm. . The oscillation wavelength was 1.064 μm, the maximum rated output was 13 W (average), the output was 90%, the frequency was 50 kHz, and the scanning speed was 1000 mm / s. This obtained the resin molded body with a groove | channel.

(Conditions for injection molding in POM and POM with glass fiber)
Pre-drying: 80 ° C, 3 hours Cylinder temperature: 200 ° C
Mold temperature: 80 ℃
Injection speed: 16mm / sec
Holding pressure: 50 MPa

(Conditions for injection molding in glass-filled PBT)
Pre-drying: 140 ° C, 3 hours Cylinder temperature: 260 ° C
Mold temperature: 60 ℃
Injection speed: 20mm / sec
Holding pressure: 50 MPa

(Conditions for injection molding in PPS with glass fiber)
Pre-drying: 140 ° C, 3 hours Cylinder temperature: 320 ° C
Mold temperature: 150 ° C
Injection speed: 20mm / sec
Holding pressure: 50 MPa

[Manufacture of resin composite moldings]
About each of the resin molded body with a groove | channel, it inserts in the metal mold | die for injection molding by making into a contact surface the surface which has the groove | channel formed by laser irradiation, and the 2nd resin composition shown in Table 3 is described in patent document 1. The resin composite molded product was obtained by injection molding under the same conditions as described in [Production of grooved resin molded article].

[Evaluation]
For each of the resin composite molded bodies 1 according to Test Example 3, the bonding strength was measured by the same method as in Test Example 1. The results are shown in FIG. In FIG. 6, each test example according to Test Example 3 has the same combination of materials as each Test Example 2 shown in Table 2 (eg, Test Example 2-1 and Test Example 3-1). ) Are shown side by side for comparison.

[Test Examples 3-1 to 3-4] First resin composition = no glass fiber In Test Examples 3-1 to 3-4, the grooved resin molded product does not contain glass fiber. It is impossible to obtain a resin composite molded article by the method described in 1. On the other hand, as shown in Test Examples 2-1 to 2-4, according to the method described in this embodiment, the first resin molded body has a bonding strength of 10 MPa or more even if it does not contain an inorganic filler. The resin composite molded body 1 can be obtained.

[Test Examples 3-5 to 3-8] Resins constituting the first resin composition = resins constituting the second resin composition Test Examples 3-5 to 3-8 and Test Examples 2-10 to 2-13 According to the comparison, the joint strength of the resin composite molded body obtained by the method described in this embodiment is equal to or higher than the joint strength of the resin composite molded body obtained by the method described in Patent Document 1.

When using the technique described in Patent Document 1, in order to remove the resin component of the grooved resin molded product by laser irradiation and form the groove, carbon black is used so that the resin portion efficiently absorbs the laser. In contrast, it is necessary to color the resin composition with a colorant such as the above, but in the invention described in the present embodiment, when the first resin molded body 10 is injection-molded by transferring the unevenness provided in the mold. Since the uneven surface 11 is formed, the color of the first resin composition can be freely set without any particular restriction, which is advantageous in that it can be applied to external parts and the like.

[Test Examples 3-9 to 3-12] Difference between cylinder temperature during resin composite molding and Vicat softening point of first resin composition (ΔT) <15 ° C.
In Test Examples 3-9 to 3-12, the first resin molded body 10 contains glass fibers. And the resin which comprises the 1st resin composition differs from the resin which comprises the 2nd resin composition, the cylinder temperature at the time of injection-molding the 2nd resin composition, and the Vicat softening point of the 1st resin composition Is less than 15 ° C.

In this case, sufficient bonding strength was not obtained by the method described in this embodiment shown in Test Examples 2-19, 2-20, 2-24, and 2-25, whereas Test Example 3-9 In the method described in Patent Document 1 shown in FIGS. 3 to 12, high bonding strength was obtained. Therefore, the bonding mechanism between the method described in this embodiment and the method described in Patent Document 1 is as follows. Can be said to be completely different.

<Test Example 4> Comparison of the shape of the uneven surface 11 and the resin material In addition to the shape of Test Example 1-2 (coefficient a (6L / bd ² ) = 38), for each shape shown in Table 4, the resin shown in Table 5 With the combination of materials, the resin composite molded body 1 was molded under the same injection mold as in Test Example 1 and the same molding conditions as in Test Example 2, and the bonding strength was measured by the same method as in Test Example 1. The results are shown in Table 5.

Here, shape 1 in Table 4 is the same shape as in Test Example 1-2.

As shown in Test Example 4-1 to Test Example 4-4 and Test Example 4-7, the value of the coefficient a (6 L / bd ² ) is 5 or more and 600 or less, and the temperature of the injection process of the second resin composition When the value of the difference (ΔT) between the first resin composition and the Vicat softening point is in the range of 15 ° C. or more and 300 ° C. or less, it was confirmed that a high bonding strength of 10 MPa or more was obtained. Further, as shown in Test Examples 4-5 and X-6, when the difference between the temperature of the injection process of the second resin composition and the Vicat softening point of the first resin composition is lower than 15 ° C., It was confirmed that only a bonding strength of less than 10 MPa can be obtained even with the coefficient a. In addition, “unmanufacturable” of a = 750 in Test Example 4-7 was impossible to test because the mold 6 was difficult to manufacture because the convex portion 13 of the shape 6 was a very long and narrow shape. Means that.

<Test Example 5> Examination of Evaluation Method for Coefficient a Coefficient a, that is, 6 L / bd ² is a dimension of a mold. On the other hand, since welding occurs at the bonding interface in the resin composite molded body, the shape of the bonded interface between the first resin molded body 10 and the second resin molded body 20 in the resin composite molded body 1 is completely the same as the dimensions of the mold. Are not the same.

However, in examining whether the technical scope of the patented invention belongs, it is difficult to prove the technical scope of the patented invention from the dimensions of the mold. It is necessary to establish a method to prove the technical scope.

As a method for evaluating the coefficient a from the resin composite molded body 1, (1) Evaluation by X-ray CT, (2) A solvent that dissolves the second resin molded body 20 without dissolving the first resin molded body 10 is used. Method of melting the second resin molded body 20 and evaluating the coefficient a for the remaining first resin molded body 10 (3) so that the boundary between the first resin molded body 10 and the second resin molded body 20 can be observed Examples include a method of cutting the resin composite molded body 1 and observing the boundary between the first resin molded body 10 and the second resin molded body 20 from the cross section after cutting. Especially, since the coefficient a can be evaluated easily and at low cost, the resin composite molded body 1 is cut so that the boundary between the (3) first resin molded body 10 and the second resin molded body 20 can be observed. It is preferable that the coefficient a can be evaluated by a method of observing the boundary between the first resin molded body 10 and the second resin molded body 20 from the cross section.

Therefore, it was examined whether the above method (3) can be adopted as an evaluation method of the coefficient a.

〔Consideration〕
The resin composite molded body 1 according to Test Example 1-3 was cut from above to below so that the boundary between the first resin molded body 10 and the second resin molded body 20 could be observed. And the boundary of the 1st resin molded object 10 and the 2nd resin molded object 20 was expanded and observed from the cross section after cutting. The results are shown in FIG.

As shown in FIG. 7, the cross-sectional shape of the resin composite molded body 1 is slightly different from the shape of the mold. This is expected because the resin composite molded body 1 is welded at the bonding interface.

However, as shown in FIG. 7, the dimensions of the bonding interface are not significantly different before and after bonding, and the coefficient a can be correctly evaluated by the method (3) above.

Therefore, in the present embodiment, as a method for evaluating the coefficient a, (3) the resin composite molded body 1 is cut so that the boundary between the first resin molded body 10 and the second resin molded body 20 can be observed. A method of observing the boundary between the first resin molded body 10 and the second resin molded body 20 from a later cross section is adopted.

<Test Example 6> Examination of the effects of molding conditions Generally, when resin molded bodies are joined by insert molding, the molding conditions such as cylinder temperature, mold temperature, injection speed, and holding pressure during secondary molding are set higher. Attempts have also been made to improve the bonding strength depending on molding conditions, such as preheating the primary molded body (first resin molded body 10). Therefore, also in this embodiment, the molding conditions were changed in a state where the shape (coefficient a) of the uneven surface 11 and the combination of resin materials (ΔT) were aligned, and the influence of the molding conditions on the bonding strength was examined.

[Primary molding]
A polyphenylene sulfide resin (product name: Durafide 1140A1, Vicat softening point: 266 ° C., manufactured by Polyplastics Co., Ltd.) was injection-molded under the following conditions, and the same as the shape 2 of Test Example 4, coefficient a (6 L / bd ² ) = 75 The 1st resin molding 10 was obtained.
(Primary molding conditions)
Pre-drying: 140 ° C, 3 hours Cylinder temperature: 320 ° C
Mold temperature: 150 ° C
Injection speed: 20mm / sec
Holding pressure: 50 MPa

[Secondary molding]
Using the uneven surface 11 of the first resin molded body 10 as a contact surface, it was inserted into the same injection mold as in Test Example 1, and a polyacetal resin (product name: Duracon M90-44, Vicat softening point: 148 ° C., polyplastics The resin composite molded body 1 was obtained by injection molding under the molding conditions shown in Table 6. Here, the molding conditions of Test Example 6-1 are the same as the molding conditions of POM with glass fibers in Test Example 2, and the items of the molding conditions are changed based on the molding conditions. In the “preheating” in the table, the first resin molded body 10 is allowed to stand on a 150 ° C. hot plate, and after waiting sufficiently for the surface temperature of the contact surface to rise to 150 ° C., an injection mold Means that it was inserted into

[Evaluation]
For each of the resin composite molded bodies 1 according to Test Example 6, the bonding strength was measured by the same method as in Test Example 1. The results are shown in Table 6.

From the results of Test Example 6 shown in Table 6, when the molding conditions were variously changed, the change in bonding strength was about 0.8 MPa at most. Here, the same combination of resin materials as in Test Example 2-24 (PPS containing glass fiber in the first resin composition, POM in the second resin composition) and Test Example 6-1 obtained under the same molding conditions However, it was confirmed that the bonding strength was improved by 1 MPa or more compared to Test Example 2-24. That is, the improvement of the bonding strength by the shape (coefficient a) of the concavo-convex surface 11 of the present embodiment can achieve a higher effect than the improvement of the bonding strength by the molding conditions.

DESCRIPTION OF SYMBOLS 1 Resin composite molded object 10 1st resin molded object 11 Irregular surface 12 Recessed part (groove)
13 Convex part (mountain)
20 Second resin molding

Claims (2)

An injection step of injecting a thermoplastic or thermosetting second resin composition onto the surface of a first resin molded body comprising a cured product of a thermoplastic first resin composition and having irregularities on the surface; 1 is a method for producing a resin composite molded body in which a resin molded body and a second resin molded body made of a cured product of the second resin composition are joined,
The difference between the temperature of the second resin composition and the Vicat softening point of the first resin molded body in the injection step is 15 ° C. or higher and 300 ° C. or lower. In the resin composite molded body, the first resin molded body The height of the projections of the projections and depressions is L (mm), the width of the projections, and the width in the direction parallel to the direction in which the second resin composition is injected is d (mm), and the second A method for producing a resin composite molded body, wherein a value of 6 L / bd ² is 5 or more and 600 or less, where b (mm) is a width in a direction perpendicular to a direction in which the resin composition is injected. The method for producing a resin composite molded body according to claim 1, wherein the resin constituting the first resin composition and the resin constituting the second resin composition are the same.

Images