TW202337955A - Polyimide resin composition and molded article - Google Patents

Abstract

The invention provides a polyimide resin composition containing: a polyimide resin (A) which contains a repeating structural unit represented by formula (1) shown below and a repeating structural unit represented by formula (2) shown below, wherein the content ratio of the repeating structural unit of formula (1) relative to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) is within a range from 20 to 70 mol%, and an amorphous resin (B) containing a repeating structural unit represented by a prescribed formula (I). The invention also provides a molded article containing this polyimide resin composition. (R1 represents a divalent group of 6 to 22 carbon atoms that includes at least one alicyclic hydrocarbon structure. R2 represents a divalent chain-like aliphatic group of 5 to 16 carbon atoms. X1 and X2 each independently represent a tetravalent group of 6 to 22 carbon atoms that includes at least one aromatic ring.).

Description

Polyimide resin composition and molded article

The present invention relates to a polyimide resin composition and a molded article.

Polyimide resin is a useful engineering plastic with high strength and high solvent resistance through the rigidity of the molecular chain, resonance stabilization, and strong chemical bonding. It is used in a wide range of fields. In addition, since crystalline polyimide resin can further improve its heat resistance, strength, and chemical resistance, it is expected to be used as a metal substitute. However, while polyimide resin has high heat resistance, it does not exhibit thermoplasticity and has a problem of low molding processability.

As for polyimide molding materials, highly heat-resistant resins such as VESPEL (registered trademark) are known (Patent Document 1). Their fluidity is extremely low even at high temperatures, so molding processing is difficult and high-temperature and high-pressure conditions are required. It takes a long time to form, so it is also disadvantageous from a cost perspective. In contrast, resins that have a melting point and fluidity at high temperatures, such as crystalline resins, can be easily and cost-effectively molded.

Therefore, in recent years, some people have reported thermoplastic polyimide resins. In addition to the inherent heat resistance of polyimide resin, thermoplastic polyimide resin also has excellent molding processability. Therefore, thermoplastic polyimide resin can also be applied to molded articles used in severe environments where commonly used thermoplastic resins such as nylon and polyester cannot be applied. For example, Patent Document 2 discloses a compound obtained by reacting a tetracarboxylic acid containing at least one aromatic ring and/or its derivatives, a diamine containing at least one alicyclic hydrocarbon structure, and a chain aliphatic diamine. Thermoplastic polyimide resin with predetermined repeating structural units.

In the field of engineering plastics, technology for mixing and alloying two or more thermoplastic resins is also known for the purpose of improving physical properties and imparting functions according to applications. Patent Document 3 discloses a thermoplastic polyimide resin containing a predetermined repeating unit. It is also described that the polyimide resin is used in combination with other resins as a polymer alloy. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2005-28524 [Patent Document 2] International Publication No. 2013/118704 [Patent Document 3] International Publication No. 2016/147996

[Problem to be solved by the invention]

The thermoplastic polyimide resin described in Patent Document 3 has crystallinity and is excellent in heat resistance, strength, chemical resistance, etc. However, depending on the application, a high level of dimensional stability in a wide temperature range is required. In this regard, There is still room for further improvement. An object of the present invention is to provide a polyimide resin composition capable of producing a molded article with a low thermal expansion coefficient and excellent dimensional stability. [Means to solve the problem]

The inventors of this case discovered a polyimide resin containing a crystalline thermoplastic polyimide resin obtained by combining specific different polyimide structural units in a specific ratio, and an amorphous resin having a specific structure. The composition can solve the above problems. That is, the present invention relates to the following. [1] A polyimide resin composition containing a polyimide resin (A) and an amorphous resin (B), the polyimide resin (A) containing a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), and the content ratio of the repeating structural unit of the formula (1) relative to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is 20 ~70 mol%, the amorphous resin (B) contains the repeating structural unit represented by the following formula (I); [Chemical 1] (R ₁ is a divalent group with 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure; R ₂ is a divalent chain aliphatic group with 5 to 16 carbon atoms; X ₁ and X ₂ are each independently It is a tetravalent group containing at least 1 aromatic ring with a carbon number of 6 to 22;) [Chemical 2] (R ₄ is a divalent group with 6 to 22 carbon atoms containing at least one aromatic ring; R ₅ is at least 1 of the divalent groups represented by any one of the following formulas (R-5a) to (R-5c) species;) [Chemical 3] (R ₅₁ is an alkyl group with 1 to 4 carbon atoms, an alkenyl group with 2 to 4 carbon atoms, or an alkynyl group with 2 to 4 carbon atoms; m ₅₁ is an integer of 0 to 2 independently, and p ₅₁ is 0 to 4 is an integer; * represents atomic bond;) [Chemistry 4] (R ₅₂ is each independently an alkyl group with 1 to 4 carbon atoms, an alkenyl group with 2 to 4 carbon atoms, or an alkynyl group with 2 to 4 carbon atoms; m ₅₂ is each independently an integer of 0 to 2, p ₅₂ is an integer independently from 0 to 4; * represents an atomic bond;) [Chemistry 5] (R ₅₃ is each independently an alkyl group or phenyl group having 1 to 4 carbon atoms; m ₅₃ is each independently an integer from 2 to 6; n is the average number of repeating structural units; * represents an atomic bond.) [2 ] A molded body containing the polyimide resin composition of [1]. [Effects of the invention]

The polyimide resin composition and molded article of the present invention have a low thermal expansion coefficient and excellent dimensional stability, and are suitable for use in films, copper-clad laminates, and electrical and electronic components that require low thermal expansion coefficients, for example.

[Polyimide resin composition] The polyimide resin composition of the present invention contains polyimide resin (A) and amorphous resin (B). The polyimide resin (A) contains the following formula The repeating structural unit represented by (1) and the repeating structural unit represented by the following formula (2), and the repeating structural unit of the formula (1) relative to the repeating structural unit of the formula (1) and the repeating structure of the formula (2) The total content ratio of units is 20 to 70 mol%, and the amorphous resin (B) contains repeating structural units represented by the following formula (I). [Chemical 6] (R ₁ is a divalent group with 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure; R ₂ is a divalent chain aliphatic group with 5 to 16 carbon atoms; X ₁ and X ₂ are each independently It is a tetravalent group with a carbon number of 6 to 22 containing at least one aromatic ring.) [Chemical 7] (R ₄ is a divalent group with 6 to 22 carbon atoms containing at least one aromatic ring; R ₅ is at least 1 of the divalent groups represented by any one of the following formulas (R-5a) to (R-5c) species.) [Chemistry 8] (R ₅₁ is an alkyl group with 1 to 4 carbon atoms, an alkenyl group with 2 to 4 carbon atoms, or an alkynyl group with 2 to 4 carbon atoms; m ₅₁ is an integer of 0 to 2 independently, and p ₅₁ is 0 to An integer of 4; * represents an atomic bond.) [Chemistry 9] (R ₅₂ is each independently an alkyl group with 1 to 4 carbon atoms, an alkenyl group with 2 to 4 carbon atoms, or an alkynyl group with 2 to 4 carbon atoms; m ₅₂ is each independently an integer of 0 to 2, p ₅₂ is an integer independently from 0 to 4; * represents an atomic bond.) [Chemistry 10] (R ₅₃ is each independently an alkyl group or phenyl group having 1 to 4 carbon atoms; m ₅₃ is each independently an integer from 2 to 6; n is the average number of repeating structural units; * represents an atomic bond.)

The polyimide resin composition of the present invention has the above-mentioned structure and can produce a molded article having a low coefficient of thermal expansion (hereinafter also referred to as "CTE") and excellent dimensional stability. The reason for this has not yet been determined, but it is thought to be as follows. Component (A) is a crystalline resin and component (B) is an amorphous resin, but both have an imine structure. Therefore, it is considered that the component (A) and the component (B) are mutually dispersible, and are mutually dispersed at the micron to nanometer level in the obtained resin composition and molded article, forming a microphase separation structure such as a sea-island structure. It is believed that a molded article in which component (A) or component (B) is finely dispersed at the micron to nanometer level is likely to disperse stress when stress is applied, so stress relaxation is likely to occur when shrinkage stress due to heating is generated. Furthermore, it is considered that the component (A) and the component (B) are resins with relatively high heat resistance among thermoplastic resins, and therefore can maintain high dimensional stability even in high temperature regions.

Pellets composed of the polyimide resin composition of the present invention, or molded articles obtained by molding the polyimide resin composition, preferably have a microphase separation structure from the viewpoint of achieving lower CTE. The microphase separation structure is formed by the phase separation of component (A) and component (B). It can be an island structure or a co-continuous structure, and is preferably an island structure. In the sea island structure, any component can form a "sea" depending on the mass ratio of component (A) and component (B) in the molded body. In this specification, whether the pellets or the formed body has a microphase separation structure can be judged by observing the surface or cross-section of the formed body with a scanning electron microscope (SEM).

<Polyimide resin (A)> The polyimide resin (A) used in the present invention contains a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), and the formula ( The content ratio of the repeating structural unit of 1) relative to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is 20 to 70 mol%. [Chemical 11] (R ₁ is a divalent group with 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure; R ₂ is a divalent chain aliphatic group with 5 to 16 carbon atoms; X ₁ and X ₂ are each independently It is a tetravalent radical with a carbon number of 6 to 22 containing at least one aromatic ring.)

The polyimide resin (A) used in the present invention is a crystalline thermoplastic resin and is preferably in the form of powder or pellets. Thermoplastic polyimide resin is a polyimide that does not have a glass transition temperature (Tg) and is formed by closing the imine ring after molding it into the state of a polyimide precursor, such as polyamide acid. resin, or polyimide resin that decomposes at a temperature lower than the glass transition temperature.

The repeating structural units of formula (1) will be described in detail below. R ₁ is a divalent group having 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure. Here, the alicyclic hydrocarbon structure means a ring derived from an alicyclic hydrocarbon compound, and the alicyclic hydrocarbon compound may be saturated or unsaturated, and may be monocyclic or polycyclic. Examples of the alicyclic hydrocarbon structure include, but are not limited to, cycloalkane rings such as cyclohexane rings, cycloolefin rings such as cyclohexene rings, bicycloalkane rings such as norbornane rings, and bicycloalkene rings such as norbornene. Wait for this. Among these, a cycloalkane ring is preferred, a cycloalkane ring having 4 to 7 carbon atoms is more preferred, and a cyclohexane ring is further preferred. The carbon number of R ₁ is 6~22, preferably 8~17. R ₁ contains at least one alicyclic hydrocarbon structure, preferably 1 to 3.

R ₁ is preferably a divalent group represented by the following formula (R1-1) or (R1-2). [Chemical 12] (m ₁₁ and m ₁₂ are each independently an integer from 0 to 2, and are preferably 0 or 1. m ₁₃ ~ m ₁₅ are each independently an integer from 0 to 2, and are preferably 0 or 1.)

R ₁ is particularly preferably a divalent group represented by the following formula (R1-3). [Chemical 13] In addition, in the divalent group represented by the above formula (R1-3), the positional relationship between the two methylene groups relative to the cyclohexane ring can be cis or trans, and the ratio of cis to trans can be to any value.

X ₁ is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. The above-mentioned aromatic ring may be a single ring or a condensed ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and a condensed tetraphenyl ring, but are not limited thereto. Among these, a benzene ring and a naphthalene ring are preferred, and a benzene ring is more preferred. The carbon number of X ₁ is 6~22, preferably 6~18. X ₁ system contains at least 1 aromatic ring, preferably 1 to 3 aromatic rings.

X ₁ is preferably a tetravalent base represented by any one of the following formulas (X-1) to (X-4). [Chemical 14] (R ₁₁ ~ R ₁₈ are each independently an alkyl group having 1 to 4 carbon atoms. _{p 11} ~ p ₁₃ are each independently an integer from 0 to 2, preferably 0. _{p 14} , p ₁₅ , p ₁₆ and p ₁₈ is each independently an integer from 0 to 3, preferably 0. p ₁₇ is an integer from 0 to 4, preferably 0. _{L 11} ~ L ₁₃ are each independently a single bond, a carbonyl group or a carbon number from 1 to 4 Alkylene group.) In addition, X ₁ is a tetravalent group with 6 to 22 carbon atoms containing at least one aromatic ring, so R ₁₂ , R ₁₃ , p ₁₂ and p ₁₃ in the formula (X-2) are represented by the formula (X-2) is selected so that the number of carbon atoms in the tetravalent base falls within the range of 10 to 22. Similarly, L ₁₁ , R ₁₄ , R ₁₅ , p ₁₄ and p ₁₅ in the formula (X-3) are such that the carbon number of the tetravalent group represented by the formula (X-3) falls within the range of 12 to 22 To select, L ₁₂ , L ₁₃ , R ₁₆ , R ₁₇ , R ₁₈ , p ₁₆ , p ₁₇ and p ₁₈ in the formula (X-4) are the carbon numbers of the tetravalent base represented by the formula (X-4) Choose a method that falls within the range of 18~22.

X ₁ is particularly preferably a tetravalent base represented by the following formula (X-5) or (X-6). [Chemical 15]

Next, the repeating structural unit of formula (2) will be described in detail below. R ₂ is a divalent chain aliphatic group having 5 to 16 carbon atoms, preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and further preferably 8 to 10 carbon atoms. Here, the chain aliphatic group refers to a group derived from a chain aliphatic compound, and the chain aliphatic compound may be saturated or unsaturated, and may be linear or branched. R ₂ is preferably an alkylene group having 5 to 16 carbon atoms, more preferably 6 to 14 carbon atoms, and further preferably an alkylene group having 7 to 12 carbon atoms, of which it is preferably an alkylene group having 8 to 10 carbon atoms. The above-mentioned alkylene group may be a straight-chain alkylene group or a branched alkylene group, and is preferably a straight-chain alkylene group. R ₂ is preferably at least one selected from the group consisting of octamethylene and decamethylene, and is particularly preferably octamethylene.

The definition of X ₂ is the same as that of X ₁ in formula (1), and the ideal form is also the same.

The content ratio of the repeating structural unit of formula (1) relative to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) is 20 to 70 mol%. When the content ratio of the repeating structural units of formula (1) is within the above range, the polyimide resin can be sufficiently crystallized even in a general injection molding cycle. If the content ratio is less than 20 mol%, the molding processability decreases, and if it exceeds 70 mol%, the crystallinity decreases, so the heat resistance decreases. The content ratio of the repeating structural unit of the formula (1) relative to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is preferably 65 mol% or less from the viewpoint of exhibiting high crystallinity, and more The content is preferably 60 mol% or less, further preferably 50 mol% or less, and further preferably less than 40 mol%. If the content ratio of the repeating structural unit of the formula (1) relative to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is 20 mol% or more and less than 40 mol%, the polyester The crystallinity of the imine resin (A) becomes higher, and a resin molded article with better heat resistance can be obtained. The above content ratio is preferably 25 mol% or more, more preferably 30 mol% or more, and further preferably 32 mol% or more from the viewpoint of molding processability. From the viewpoint of exhibiting high crystallinity, it is more preferably 35 mol%. Ear% or less.

The total ratio of the repeating structural units of the formula (1) and the repeating structural units of the formula (2) relative to the content ratio of all the repeating structural units constituting the polyimide resin (A) is preferably 50 to 100 mol%, more preferably It is 75~100 mol%, preferably 80~100 mol%, further preferably 85~100 mol%.

The polyimide resin (A) may further contain a repeating structural unit of the following formula (3). In this case, the content ratio of the repeating structural unit of formula (3) relative to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) is preferably 25 mol% or less. On the other hand, the lower limit is not particularly limited, as long as it exceeds 0 mol%. In the case where the repeating structural unit of formula (3) is contained, the above content ratio is preferably 5 mol% or more, more preferably 10 mol% or more, from the viewpoint of improving heat resistance, and on the other hand, from the viewpoint of maintaining crystallinity. , preferably less than 20 mol%, more preferably less than 15 mol%. [Chemical 16] (R ₃ is a divalent group with a carbon number of 6 to 22 containing at least one aromatic ring. X ₃ is a tetravalent group with a carbon number of 6 to 22 containing at least one aromatic ring.)

R ₃ is a divalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. The above-mentioned aromatic ring may be a single ring or a condensed ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and a condensed tetraphenyl ring, but are not limited thereto. Among these, a benzene ring and a naphthalene ring are preferred, and a benzene ring is more preferred. The carbon number of _R3 is 6~22, preferably 6~18. R ₃ contains at least 1 aromatic ring, preferably 1 to 3.

R ₃ is preferably a divalent group represented by the following formula (R3-1) or (R3-2). [Chemical 17] (m ₃₁ and m ₃₂ are each independently an integer from 0 to 2, preferably 0 or 1. _{m 33} and m ₃₄ are each independently an integer from 0 to 2, preferably 0 or 1. R ₂₁ , R ₂₂ , and R ₂₃ are each independently an alkyl group with 1 to 4 carbon atoms, an alkenyl group with 2 to 4 carbon atoms, or an alkynyl group with 2 to 4 carbon atoms. _{p 21} , p ₂₂ and p ₂₃ are 0 to 4 An integer, preferably 0. L ₂₁ is a single bond, a carbonyl group or an alkylene group with 1 to 4 carbon atoms.) In addition, R ₃ is a divalent group with 6 to 22 carbon atoms containing at least one aromatic ring, so the formula ( m ₃₁ , m ₃₂ , R ₂₁ and p ₂₁ in R3-1) are selected so that the carbon number of the divalent group represented by the formula (R3-1) falls within the range of 6 to 22. Similarly, L ₂₁ , m ₃₃ , m ₃₄ , R ₂₂ , R ₂₃ , p ₂₂ and p ₂₃ in the formula (R3-2) are divalent radicals represented by the formula (R3-2) whose carbon number falls within 12 Choose within the range of ~22.

The definition of X ₃ is the same as that of X ₁ in formula (1), and the ideal form is also the same.

The terminal structure of the polyimide resin (A) is not particularly limited, but it is preferably a chain aliphatic group having 5 to 14 carbon atoms at the terminal. The chain aliphatic group may be saturated or unsaturated, and may be linear or branched. If the polyimide resin (A) has the above-mentioned specific group at the terminal, a resin composition excellent in heat aging resistance can be obtained. As for the saturated chain aliphatic group having 5 to 14 carbon atoms, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, lauryl, n-Tridecyl, n-tetradecyl, isopentyl, neopentyl, 2-methylpentyl, 2-methylhexyl, 2-ethylpentyl, 3-ethylpentyl, isooctyl , 2-ethylhexyl, 3-ethylhexyl, isononyl, 2-ethyloctyl, isodecyl, isododecyl, isotridecyl, isotetradecyl, etc. Examples of the unsaturated chain aliphatic group having 5 to 14 carbon atoms include 1-pentenyl, 2-pentenyl, 1-hexenyl, 2-hexenyl, 1-heptenyl, 2 - Heptenyl, 1-octenyl, 2-octenyl, nonenyl, decenyl, dodecenyl, tridecenyl, tetradecenyl, etc. Among them, the above-mentioned chain aliphatic group is preferably a saturated chain aliphatic group, and more preferably a saturated linear aliphatic group. From the viewpoint of obtaining heat aging resistance, the chain aliphatic group preferably has a carbon number of 6 or more, more preferably a carbon number of 7 or more, further preferably a carbon number of 8 or more, preferably a carbon number of 12 or less, and more preferably a carbon number of 10 below, and more preferably the number of carbon atoms is 9 or less. There may be only one type of said chain aliphatic group, or 2 or more types may be sufficient. The above-mentioned chain aliphatic group is particularly preferably at least one selected from the group consisting of n-octyl, isooctyl, 2-ethylhexyl, n-nonyl, isononyl, n-decyl, and isodecyl. 1 type, more preferably at least one type selected from the group consisting of n-octyl, isooctyl, 2-ethylhexyl, n-nonyl, and isononyl, and most preferably at least one type selected from the group consisting of At least one kind from the group consisting of n-octyl, isooctyl, and 2-ethylhexyl. In addition, from the viewpoint of heat aging resistance, the polyimide resin (A) preferably has only a chain aliphatic group having 5 to 14 carbon atoms at its terminal in addition to a terminal amine group and a terminal carboxyl group. When the terminal has a group other than the above, its content is preferably 10 mol% or less, more preferably 5 mol% or less based on the chain aliphatic group having 5 to 14 carbon atoms.

The content of the above-mentioned chain aliphatic group having 5 to 14 carbon atoms in the polyimide resin (A) is relative to the entire repeating structure constituting the polyimide resin (A) from the viewpoint of exhibiting excellent heat aging resistance. The total 100 mol% of the units is preferably 0.01 mol% or more, more preferably 0.1 mol% or more, and further preferably 0.2 mol% or more. In addition, in order to obtain good mechanical properties ensuring a sufficient molecular weight, the content of the above-mentioned chain aliphatic group having 5 to 14 carbon atoms in the polyimide resin (A) must be increased relative to the amount of the chain aliphatic group constituting the polyimide resin (A). The total 100 mol% of all repeating structural units is preferably 10 mol% or less, more preferably 6 mol% or less, further preferably 3.5 mol% or less, further preferably 2.0 mol% or less, still further It is preferably 1.2 mol% or less. The content of the chain aliphatic group having 5 to 14 carbon atoms in the polyimide resin (A) can be determined by depolymerizing the polyimide resin (A).

The polyimide resin (A) preferably has a melting point of 360°C or lower and a glass transition temperature of 150°C or higher. The melting point of the polyimide resin (A) is preferably 280°C or higher, more preferably 290°C or higher from the viewpoint of heat resistance, and is preferably 345°C or lower, more preferably 340°C from the viewpoint of exhibiting high molding processability. ℃ or lower, more preferably 335°C or lower. In addition, the glass transition temperature of the polyimide resin (A) is more preferably 160°C or higher from the viewpoint of heat resistance, and further preferably 170°C or higher, and is preferably 250°C or lower from the viewpoint of exhibiting high molding processability. The temperature is more preferably 230°C or lower, further preferably 200°C or lower. In addition, the polyimide resin (A) was measured with a differential scanning calorimeter from the viewpoint of improving crystallinity, heat resistance, mechanical strength, and chemical resistance. After the polyimide resin was melted, the temperature was reduced at a cooling rate The amount of heat at the crystallization exothermic peak observed during cooling at 20°C/min (hereinafter also referred to as "crystallization exothermic heat") is preferably 5.0 mJ/mg or more, more preferably 10.0 mJ/mg or more, and further preferably 17.0 mJ/mg or above. The upper limit of the crystallization heat release amount is not particularly limited, but is usually 45.0 mJ/mg or less. The melting point, glass transition temperature, and crystallization heat release amount of the polyimide resin (A) can all be measured by a differential scanning calorimeter. Specifically, they can be measured by the method described in the Examples.

The weight average molecular weight Mw of the polyimide resin (A) is preferably 10,000~150,000, more preferably 15,000~100,000, further preferably 20,000~80,000, further preferably 30,000~70,000, further preferably 35,000~65,000. . If the weight average molecular weight Mw of the polyimide resin (A) is 10,000 or more, the mechanical strength of the obtained molded article becomes good, and if it is 40,000 or more, the stability of the mechanical strength becomes good, and at the same time, the above-mentioned microstructure is easily formed. Phase separation structure can achieve lower CTE. In addition, when it is 150,000 or less, the formability becomes good. The weight average molecular weight Mw of the polyimide resin (A) can be measured by gel filtration chromatography (GPC) using polymethyl methacrylate (PMMA) as a standard. Specifically, it can be measured by Measured using the method described in the example.

The logarithmic viscosity of the 0.5 mass% concentrated sulfuric acid solution of the polyimide resin (A) at 30°C is preferably in the range of 0.8 to 2.0 dL/g, and more preferably in the range of 0.9 to 1.8 dL/g. If the logarithmic viscosity is 0.8dL/g or more, sufficient mechanical strength can be obtained when forming a molded body. When the logarithmic viscosity is 2.0 dL/g or less, the molding processability and workability become good. Using a Cannon-Fenske viscometer, measure the flow time of concentrated sulfuric acid and the above-mentioned polyimide resin solution at 30°C, and calculate the logarithmic viscosity μ according to the following formula. μ=ln[(ts/t ₀ )/C] t ₀ : flow time of concentrated sulfuric acid ts: flow time of polyimide resin solution C: 0.5 (g/dL)

(Production method of polyimide resin (A)) Polyimide resin (A) can be produced by reacting a tetracarboxylic acid component and a diamine component. The tetracarboxylic acid component contains tetracarboxylic acid containing at least one aromatic ring and/or its derivatives, and the diamine component contains a diamine containing at least one alicyclic hydrocarbon structure and a chain aliphatic diamine.

The tetracarboxylic acid containing at least one aromatic ring is preferably a compound with four carboxyl groups directly bonded to the aromatic ring, and may also contain an alkyl group in the structure. In addition, the above-mentioned tetracarboxylic acid preferably has 6 to 26 carbon atoms. As the above-mentioned tetracarboxylic acid, pyromellitic acid, 2,3,5,6-toluenetetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 3,3',4,4 '-Biphenyltetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, etc. Among these, pyromellitic acid is more preferred.

Examples of derivatives of tetracarboxylic acids containing at least one aromatic ring include acid anhydrides or alkyl esters of tetracarboxylic acids containing at least one aromatic ring. The above-mentioned tetracarboxylic acid derivative is preferably one having 6 to 38 carbon atoms. Examples of tetracarboxylic acid anhydrides include pyromellitic acid monoanhydride, pyromellitic acid dianhydride, 2,3,5,6-toluenetetracarboxylic acid dianhydride, and 3,3',4,4'-diphenyl Tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 1,4,5,8 -Naphthalene tetracarboxylic dianhydride, etc. Examples of alkyl esters of tetracarboxylic acids include pyromellitic acid dimethyl ester, pyromellitic acid diethyl ester, pyromellitic acid dipropyl ester, pyromellitic acid diisopropyl ester, 2,3 ,5,6-Toluene tetracarboxylic acid dimethyl ester, 3,3',4,4'-diphenyltetracarboxylic acid dimethyl ester, 3,3',4,4'-benzophenone tetracarboxylic acid dimethyl ester Ester, 3,3',4,4'-biphenyltetracarboxylic acid dimethyl ester, 1,4,5,8-naphthalene tetracarboxylic acid dimethyl ester, etc. In the alkyl ester of the above-mentioned tetracarboxylic acid, the carbon number of the alkyl group is preferably 1 to 3.

The tetracarboxylic acid containing at least one aromatic ring and/or its derivatives may be used alone or in combination of at least one compound selected from the above.

The carbon number of the diamine containing at least one alicyclic hydrocarbon structure is preferably 6 to 22, for example, 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl) Cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4 ,4'-Diaminodicyclohexylmethane, 4,4'-methylenebis(2-methylcyclohexylamine), carbodiamine, limonene diamine, isophorone diamine, norbornane diamine Amine, bis(aminomethyl)tricyclo[5.2.1.0 ^2,6 ]decane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-dicyclohexylmethane Aminodicyclohexylpropane, etc. These compounds can be used alone, or two or more compounds selected from these can be used in combination. Among these, 1,3-bis(aminomethyl)cyclohexane can be suitably used. In addition, diamines containing an alicyclic hydrocarbon structure generally have structural isomers, but the ratio of cis isomer/trans isomer is not limited.

The chain aliphatic diamine can be linear or branched, and the carbon number is preferably 5 to 16, more preferably 6 to 14, and further preferably 7 to 12. Examples of chain aliphatic diamines include 1,5-pentamethylenediamine, 2-methylpentane-1,5-diamine, and 3-methylpentane-1,5-diamine. Amine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10- Decamethylenediamine, 1,11-undecanediamine, 1,12-dodedecanediamine, 1,13-tridedecylenediamine, 1,14-tetradecamide Methyldiamine, 1,16-hexadecamethylenediamine, 2,2'-(ethyldioxy)bis(ethylamine), etc. One type of chain aliphatic diamine may be used, or a plurality of types may be mixed and used. Among these, chain aliphatic diamines having a carbon number of 8 to 10 can be suitably used, and in particular, chain aliphatic diamines selected from the group consisting of 1,8-octamethylenediamine and 1,10-decamethylenediamine can be suitably used. At least one of the group consisting of amines.

When producing the polyimide resin (A), the amount of the diamine containing at least one alicyclic hydrocarbon structure is added relative to the total amount of the diamine containing at least one alicyclic hydrocarbon structure and the chain aliphatic diamine. The molar ratio should be 20~70 mol%. The molar amount is preferably 25 mol% or more, more preferably 30 mol% or more, and further preferably 32 mol% or more. From the viewpoint of exhibiting high crystallinity, it is preferably 60 mol% or less, more preferably 50 mol%. Mol% or less, preferably less than 40 Mol%, further preferably less than 35 Mol%.

In addition, the diamine component described above may also contain a diamine containing at least one aromatic ring. The carbon number of the diamine containing at least one aromatic ring is preferably 6 to 22, and examples include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 1,2-diethynylphenylenediamine, 1,3-Diethynylphenylenediamine, 1,4-Diethynylphenylenediamine, 1,2-diaminobenzene, 1,3-diaminobenzene, 1,4-diaminobenzene, 4 ,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, α,α'-bis(4-aminobenzene base) 1,4-diisopropylbenzene, α,α'-bis(3-aminophenyl)-1,4-diisopropylbenzene, 2,2-bis[4-(4-amino Phenoxy)phenyl]propane, 2,6-diaminonaphthalene, 1,5-diaminonaphthalene, etc.

Among the above, the molar ratio of the added amount of the diamine containing at least one aromatic ring to the total amount of the diamine containing at least one alicyclic hydrocarbon structure and the chain aliphatic diamine is preferably 25 mol%. or below, more preferably 20 mol% or below, further preferably 15 mol% or below. The upper limit of the molar ratio is not particularly limited, but from the viewpoint of improving heat resistance, it is preferably 5 mol% or more, and more preferably 10 mol% or more. On the other hand, from the viewpoint of reducing the coloration of the polyimide resin, the molar ratio is more preferably 12 mol% or less, further preferably 10 mol% or less, further preferably 5 mol% or less, and still more preferably It should be 0 mol%.

When producing the polyimide resin (A), the addition amount ratio of the above-mentioned tetracarboxylic acid component to the above-mentioned diamine component is preferably 0.9 to 1.1 mole per mole of the diamine component per 1 mole of the tetracarboxylic acid component.

In addition, when producing the polyimide resin (A), in addition to the above-mentioned tetracarboxylic acid component and the above-mentioned diamine component, a terminal blocking agent may be further mixed. The blocking agent is preferably at least one selected from the group consisting of monoamines and dicarboxylic acids. The amount of the end-capping agent used is an amount that can introduce a desired amount of terminal groups into the polyimide resin (A). It is preferably 0.0001 based on 1 mol of the above-mentioned tetracarboxylic acid and/or its derivatives. ~0.1 mole, more preferably 0.001~0.06 mole, further preferably 0.002~0.035 mole, more preferably 0.002~0.020 mole, further preferably 0.002~0.012 mole. Among them, the end-capping agent is preferably a monoamine-based end-capping agent. From the viewpoint of improving the heat aging resistance by introducing the above-mentioned chain aliphatic group having 5 to 14 carbon atoms at the terminal of the polyimide resin (A), it is preferably The monoamine having a chain aliphatic group having 5 to 14 carbon atoms is more preferably a monoamine having a saturated linear aliphatic group having 5 to 14 carbon atoms. The blocking agent is particularly preferably selected from the group consisting of n-octylamine, isooctylamine, 2-ethylhexylamine, n-nonylamine, isononylamine, n-decylamine, and isodecylamine. At least one of the group is preferably at least one selected from the group consisting of n-octylamine, isooctylamine, 2-ethylhexylamine, n-nonylamine, and isononylamine. , preferably at least one selected from the group consisting of n-octylamine, isooctylamine, and 2-ethylhexylamine.

As the polymerization method for producing the polyimide resin (A), a known polymerization method can be used, and the method described in International Publication No. 2016/147996 can be used.

<Amorphous resin (B)> The amorphous resin (B) used in the present invention contains a repeating structural unit represented by the following formula (I). [Chemical 18] (R ₄ is a divalent group with 6 to 22 carbon atoms containing at least one aromatic ring; R ₅ is at least 1 of the divalent groups represented by any one of the following formulas (R-5a) to (R-5c) species.) [Chemical 19] (R ₅₁ is an alkyl group with 1 to 4 carbon atoms, an alkenyl group with 2 to 4 carbon atoms, or an alkynyl group with 2 to 4 carbon atoms; m ₅₁ is an integer of 0 to 2 independently, and p ₅₁ is 0 to 4 as an integer; * indicates atomic bond) [Chemistry 20] (R ₅₂ is each independently an alkyl group with 1 to 4 carbon atoms, an alkenyl group with 2 to 4 carbon atoms, or an alkynyl group with 2 to 4 carbon atoms; m ₅₂ is each independently an integer of 0 to 2, p ₅₂ is an integer independently from 0 to 4; * represents an atomic bond.) [Chemistry 21] (R ₅₃ is each independently an alkyl group or phenyl group having 1 to 4 carbon atoms; m ₅₃ is each independently an integer from 2 to 6; n is the average number of repeating structural units; * represents an atomic bond.) The present invention The polyimide resin composition contains polyimide resin (A) and amorphous resin (B) with a specific structure, so that a molded article with low CTE can be produced.

In formula (I), from the viewpoint of achieving a lower CTE, R ₄ is preferably a divalent group having 12 to 22 carbon atoms containing two or more aromatic rings, and is more preferably the following formula (R-4a) to (R The divalent base represented by any one of -4c) is further preferably a divalent base represented by the following formula (R-4a). [Chemistry 22] (In the above formula, * represents atomic bond.)

Examples of the alkyl group having 1 to 4 carbon atoms in R ₅₁ of formula (R-5a), R ₅₂ of formula (R-5b), and R ₅₃ of formula (R-5c) include methyl group and ethyl group. , n-propyl, isopropyl, n-butyl, isobutyl, second butyl, and third butyl.

In formula (R-5a), from the viewpoint of achieving a lower CTE, R ⁵¹ is preferably an alkyl group with 1 to 4 carbon atoms, more preferably an alkyl group with 1 to 3 carbon atoms, and further preferably a methyl group or an ethyl group. , further preferably methyl. m ₅₁ is preferably 0 or 1, more preferably 0, and p ₅₁ is preferably an integer from 0 to 2, more preferably 0 or 1, and further preferably 0.

In formula (R-5b), from the viewpoint of achieving a lower CTE, R ₅₂ is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group or an ethyl group. , more preferably methyl. m ₅₂ is preferably 0 or 1, more preferably 0, and p ₅₂ is preferably an integer from 0 to 2, more preferably 0 or 1, and further preferably 0.

In the formula (R-5c), from the viewpoint of achieving a lower CTE, R ₅₃ is each independently preferably a methyl group or a phenyl group, and more preferably a methyl group. Each of m ₅₃ is independently preferably an integer of 2 to 4, and more preferably 3. n is preferably a number from 2 to 5,000.

R ₅ in formula (I) may have two or more types of divalent groups represented by any one of the above formulas (R-5a) to (R-5c). From the viewpoint of achieving a lower CTE, R ₅ is preferably a divalent base represented by formula (R-5a), a divalent base represented by formula (R-5b), or a divalent base represented by formula (R-5a) and A combination of two valent bases represented by formula (R-5c).

Specific examples of the amorphous resin (B) include amorphous resins selected from the group consisting of amorphous resins containing repeating structural units represented by the following formula (B1), and amorphous resins containing repeating structural units represented by the following formula (B2). At least one kind from the group consisting of a resin and an amorphous resin containing a repeating structural unit represented by the following formula (B3). [Chemistry 23] [Chemistry 24] [Chemical 25] (In formula (B3), n represents the average number of repeating structural units.) Hereinafter, the amorphous resin containing the repeating structural unit represented by formula (B1) will also be referred to as "amorphous resin (B1)", and the amorphous resin containing the formula (B1) will be referred to as "amorphous resin (B1)". The amorphous resin having the repeating structural unit represented by (B2) is called "amorphous resin (B2)", and the amorphous resin containing the repeating structural unit represented by formula (B3) is called "amorphous resin (B3)". )".

The melt flow rate (MFR) of the amorphous resins (B1) to (B3) is preferably in the following range from the viewpoint of improving the formability of the polyimide resin composition and achieving a lower CTE. The MFR of amorphous resin (B1) measured in accordance with ASTM D1238 at a temperature of 337°C and a load of 6.6kgf should be 5~20g/10min, more preferably 5~15g/10min. The MFR of amorphous resin (B2) measured in accordance with ASTM D1238 at a temperature of 367°C and a load of 6.6kgf should be 10~30g/10min, more preferably 10~20g/10min. The MFR of amorphous resin (B3) measured in accordance with ASTM D1238 at a temperature of 295°C and a load of 6.6kgf should be 3~20g/10min, more preferably 5~15g/10min.

The content of the repeating structural unit represented by the above-mentioned formula (I) (preferably the repeating structural unit represented by any one of the above-mentioned formulas (B1) to (B3)) in the amorphous resin (B) is considered to achieve a lower CTE. From the viewpoint of reducing water absorption, it is preferably 50 mass% or more, more preferably 70 mass% or more, further preferably 80 mass% or more, further preferably 90 mass% or more, more preferably 95 mass% or more, and It is 100 mass % or less.

Component (B) can be used 1 type or 2 or more types. Among the above, component (B) is preferably at least one selected from the group consisting of amorphous resins (B1) to (B3) from the viewpoint of achieving lower CTE and reducing water absorption. One kind, more preferably at least one kind selected from the group consisting of amorphous resin (B1) and amorphous resin (B3), more preferably amorphous resin (B3).

＜Mass Ratio＞ The mass ratio of the polyimide resin (A) in the polyimide resin composition to the total mass of the polyimide resin (A) and the amorphous resin (B) [(A)/{(A) +(B)}], from the viewpoint of obtaining the effects of the present invention, it is preferably 0.01 or more and 0.99 or less. From the viewpoint of further reducing water absorption, this mass ratio is more preferably 0.1 or more, further preferably 0.2 or more, further preferably 0.25 or more, further preferably 0.30 or more, further preferably 0.40 or more, further preferably 0.45 or more, and is considered to be achieved. From the viewpoint of lower CTE, it is more preferably 0.9 or less, further preferably 0.8 or less, further preferably 0.75 or less, further preferably 0.70 or less, further preferably 0.60 or less, further preferably 0.55 or less.

The total content of the polyimide resin (A) and the amorphous resin (B) in the polyimide resin composition is preferably 50% by mass or more, more preferably 70% by mass, from the viewpoint of obtaining the effects of the present invention. % or more, preferably 80 mass% or more, further preferably 90 mass% or more, and 100 mass% or less.

＜Additive＞ The polyimide resin composition of the present invention may also contain fillers, reinforcing fibers, matting agents, nucleating agents, plasticizers, antistatic agents, anti-coloring agents, anti-gelling agents, and flame retardants according to requirements. , colorants, sliding properties improvers, antioxidants, ultraviolet absorbers, conductive agents, resin modifiers and other additives. The content of the above-mentioned additives is not particularly limited. From the viewpoint of exhibiting the effects of the additives while maintaining the physical properties derived from the polyimide resin (A) and the amorphous resin (B), polyimide resin compositions are generally It is 50 mass % or less, preferably 0.0001 to 30 mass %, more preferably 0.0001 to 15 mass %, further preferably 0.001 to 10 mass %.

The polyimide resin composition of the present invention can be made into any form, preferably into pellets. Polyimide resin (A) and amorphous resin (B) have thermoplasticity, so for example, polyimide resin (A), amorphous resin (B), and various optional ingredients according to needs are placed in an extruder. It is melt-kneaded and extruded into strands, and the strands are sheared to be pelletized. In addition, by introducing the obtained pellets into various molding machines and thermoforming them by the method described below, a molded body having a desired shape can be easily produced.

The glass transition temperature of the polyimide resin composition of the present invention is preferably 160°C or higher from the viewpoint of heat resistance, more preferably 170°C or higher, and further preferably 180°C or higher from the viewpoint of exhibiting high formability and processability. It is preferably below 250°C, more preferably below 240°C. The glass transition temperature can be measured by the same method as above.

＜Coefficient of thermal expansion (CTE)＞ The polyimide resin composition according to the present invention can produce molded articles with low CTE. For example, the absolute value of the thermal expansion coefficient measured in accordance with JIS K7197:2012 for a 4 mm thick molded body obtained by molding a polyimide resin composition is ideally 60 ppm/°C or less. The measurement temperature range of CTE is the range of 150~210℃ or 150~220℃. When using the above-mentioned amorphous resin (B1) as the amorphous resin (B), it is preferably in the range of 150~210℃. The case where at least one type is selected from the group consisting of the above-mentioned amorphous resins (B2) and (B3) is in the range of 150 to 220°C. In addition, if the molded article is stretched, the CTE value will change. Therefore, the molded article used in the CTE measurement is preferably a molded article without stretching, and more preferably an injection molded article. In injection molded products, there may be a flow direction (MD) and a direction perpendicular to the flow direction (TD), and the CTE in MD and TD may be different. In this case, the absolute value of the thermal expansion coefficient of at least one of MD or TD is preferably 60 ppm/°C or less, and more preferably the absolute value of the thermal expansion coefficient of both MD and TD is 60 ppm/°C or less.

In an injection molded article with a thickness of 4 mm obtained by molding a polyimide resin composition, the absolute value of the thermal expansion coefficient, which is lower in MD and TD, is more preferably 55 ppm/°C or less, further preferably 50 ppm/°C or less. , further preferably below 45ppm/℃, further preferably below 40ppm/℃, further preferably below 35ppm/℃, further preferably below 30ppm/℃, further preferably below 20ppm/℃, further preferably below 15ppm/℃ or less, preferably 10ppm/℃ or less. In addition, in an injection molded article with a thickness of 4 mm obtained by molding the polyimide resin composition, the total value of the absolute values of the above-mentioned thermal expansion coefficients that can be made into MD and TD is preferably 100 ppm/°C or less, and more preferably 95 ppm/ °C or lower, more preferably 90 ppm/°C or lower, further preferably 80 ppm/°C or lower, further preferably 70 ppm/°C or lower, further preferably 60 ppm/°C or lower. The thermal expansion coefficient of the molded article is a value measured in the compression mode by thermomechanical analysis (TMA method), and is specifically measured by the method described in the Examples.

<Water Absorption Rate> According to the polyimide resin composition of the present invention, a molded article with low water absorption rate can be produced. For example, the polyimide resin composition can be molded into a 30 mm × 20 mm × 4 mm thick molded article. The water absorption rate measured in accordance with JIS K7209: 2000 after being immersed in water at 23°C for 24 hours is preferably 0.30% or less. , more preferably 0.25% or less, further preferably 0.20% or less, further preferably 0.17% or less. The above-mentioned water absorption rate is a value calculated by the following formula, assuming that the mass of the molded article before immersion in water is (W ₀ ) and the mass of the molded article after immersing in water at 23° C. for 24 hours is (W ₁ ). . Water absorption (%) = [(W ₁ -W ₀ )/W ₀ ]×100 The above water absorption can be measured specifically by the method described in the Examples.

[molded body] The present invention provides a molded article containing the above-mentioned polyimide resin composition. The polyimide resin composition of the present invention has thermoplasticity, so the molded body of the present invention can be easily produced by thermoforming. Examples of thermoforming methods include injection molding, extrusion molding, blow molding, hot press molding, vacuum molding, air pressure molding, laser molding, welding, fusion bonding, etc. As long as the molding method is a thermal melting step, Any method can be used for shaping. The molding temperature varies depending on the thermal characteristics (melting point and glass transition temperature) of the polyimide resin composition. For example, in injection molding, the molding temperature can be less than 400°C and the mold temperature can be less than 220°C.

The method for producing a molded body preferably includes a step of thermoforming the polyimide resin composition at a temperature of less than 400°C. As a specific process, the following method can be mentioned. First, for the polyimide resin (A), add the amorphous resin (B) and various optional ingredients according to the needs, dry blend them, and then introduce them into the extruder, preferably at a temperature of less than 400°C. Melt it in an extruder for melting, kneading and extrusion to produce pellets. Alternatively, the polyimide resin (A) can also be introduced into the extruder, preferably melted at less than 400°C, and the amorphous resin (B) and various optional ingredients can be introduced into the extruder and The polyimide resin (A) is melt-kneaded and extruded to produce the aforementioned pellets. After drying the above-mentioned pellets, they are introduced into various molding machines and are preferably thermoformed at a temperature of less than 400° C. to produce a molded body having a desired shape.

The forming system of the present invention has a low thermal expansion coefficient, excellent dimensional stability, and even lower water absorption. For example, it is suitable for use in films, copper-clad laminates, and electrical and electronic components that require low thermal expansion coefficients. [Example]

Next, the present invention will be described in more detail using examples, but the present invention is not limited thereto. In addition, various measurements and evaluations in each Production Example and Example were performed as follows.

＜Infrared spectroscopic analysis (IR measurement)＞ The IR measurement of the polyimide resin was performed using "JIR-WINSPEC50" manufactured by JEOL Ltd.

<Logarithmic viscosity μ> Polyimide resin was dried at 190 to 200°C for 2 hours, and then 0.100 g of the polyimide resin was dissolved in 20 mL of concentrated sulfuric acid (96%, manufactured by Kanto Chemical Co., Ltd.). The imine resin solution was used as a measurement sample and measured at 30°C using a Cannon-Fenske viscometer. The logarithmic viscosity μ is calculated by the following formula. μ=ln[(ts/t ₀ )/C] t ₀ : flow time of concentrated sulfuric acid ts: flow time of polyimide resin solution C: 0.5g/dL

＜Melting point, glass transition temperature, crystallization temperature, crystallization heat release＞ The melting point Tm of the polyimide resin, the glass transition temperature Tg, the crystallization temperature Tc, and the crystallization heat release amount ΔHm of the polyimide resin, amorphous resin, and the polyimide resin composition were determined using differential scanning. Measurement was performed using a calorimeter device ("DSC-6220" manufactured by SII NanoTechnology Inc). In the measurement of crystallization temperature Tc, resin powder is used as the measurement sample for polyimide resin and amorphous resin (B1), and for amorphous resin (B2), amorphous resin (B3), and polyimide resin The imine resin composition system uses pellets as measurement samples. Under a nitrogen atmosphere, the thermal history of the measurement sample was carried out under the following conditions. The conditions of the thermal history are heating for the first time (heating rate 10℃/min), then cooling (cooling rate 20℃/min), and then heating for the second time (heating rate 10℃/min). The melting point Tm is determined by reading the peak value of the endothermic peak observed at the second temperature increase. The glass transition temperature Tg is determined by reading the value observed at the second temperature increase. The crystallization temperature Tc is determined by reading the peak value of the exothermic peak observed during cooling. In addition, regarding Tm, Tg, and Tc, if multiple peaks are observed, the peak top value of each peak is read. In addition, the crystallization heat release amount ΔHm (mJ/mg) is calculated from the area of the heat release peak observed during cooling.

＜Half-crystallization time＞ The half-crystallization time of the polyimide resin was measured using a differential scanning calorimeter device ("DSC-6220" manufactured by SII NanoTechnology Inc.). Under a nitrogen atmosphere, keep the polyimide resin at 420°C for 10 minutes, and after the polyimide resin is completely melted, perform a rapid cooling operation with a cooling rate of 70°C/min. Calculate the time from when the observed crystallization peak appears to when it reaches the top of the peak. time spent. In addition, in Table 1, the case where the half-crystallization time is 20 seconds or less is expressed as "<20".

＜Weight average molecular weight＞ The weight average molecular weight (Mw) of the polyimide resin was measured under the following conditions using a gel permeation chromatography (GPC) measurement device "Shodex GPC-101" manufactured by Showa Denko Co., Ltd. Column: Shodex HFIP-806M Mobile phase solvent: hexafluoroisopropanol (HFIP) containing 2mM sodium trifluoroacetate Tube string temperature: 40℃ Mobile phase flow rate: 1.0mL/min Sample concentration: approximately 0.1% by mass Detector: IR detector Injection volume: 100μm Calibration line: standard PMMA

＜Water Absorption Rate＞ The water absorption rate is measured in accordance with JIS K7209:2000. Using the polyimide resin of Production Example 1, the amorphous resin, or the polyimide resin composition produced in each example, an injection molded body was produced by the method described below, and cut into a size of 30 mm × 20 mm × 4 mm thickness. Condition it for more than 24 hours in an environment of 23°C and 50% relative humidity before use in the measurement. The above-mentioned molded body was dried in a hot air circulation oven at 50°C for 24 hours, then returned to room temperature in a desiccator, and the mass (W ₀ ) was measured at 23°C and a relative humidity of 50%. Then, the molded body was immersed in water at 23° C. for 24 hours, and the moisture on the surface was wiped off, and the mass (W ₁ ) after 1 minute was measured. The water absorption rate was calculated according to the following formula, and the average value of three measurements is shown in Table 2. Water absorption (%)=[(W ₁ -W ₀ )/W ₀ ]×100

＜Coefficient of thermal expansion (CTE)＞ CTE is measured in accordance with JIS K7197:2012. Using the polyimide resin of Production Example 1, the amorphous resin, or the polyimide resin composition produced in each example, an injection molded body was produced by the method described below, and cut into a size of 5 mm × 4 mm × 10 mm. under measurement. The above-mentioned injection molded body was used as a measurement sample, and a thermomechanical analysis device "TMA7100C" manufactured by Hitachi High-Tech Science Corporation was used in a nitrogen gas flow (150 mL/min) in the compression mode at a load of 49 mN and a temperature rise rate of 5°C/min. Under the same conditions, the temperature was raised from 23°C to 300°C for thermomechanical analysis (TMA) measurement. The TMA measurement is performed on the flow direction (MD) and the direction perpendicular to the flow direction (TD) of the injection molded body, and the CTE is calculated from the measured value at 150~210℃ or 150~220℃.

Production Example 1 (Production of Polyimide Resin 1) In a 2L separable flask equipped with a Dean-Stark apparatus, a Liebig condenser, a thermocouple, and four blades 500g of 2-(2-methoxyethoxy)ethanol (manufactured by Nippon Emulsifier Co., Ltd.) and 218.12g (1.00mol) of pyromellitic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were introduced, and nitrogen was circulated Then, stir at 150 rpm to form a uniform suspended solution. On the other hand, using a 500 mL beaker, 49.79 g (0.35 mol) of 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd., cis/trans ratio = 7/3), 93.77 g (0.65 mol) of 1,8-octamethylenediamine (manufactured by Kanto Chemical Co., Ltd.) was dissolved in 250 g of 2-(2-methoxyethoxy)ethanol to prepare a mixed diamine solution. The mixed diamine solution was slowly added using a plunger pump. Heat will be generated due to dropwise addition, so adjust to maintain the internal temperature within 40~80℃. The dripping system of the mixed diamine solution was set to a nitrogen flow state throughout, and the stirring blade rotation speed was set to 250 rpm. After the dropping was completed, 130 g of 2-(2-methoxyethoxy)ethanol and 1.284 g (0.010 mol) of n-octylamine (manufactured by Kanto Chemical Co., Ltd.) as an end-capping agent were added and stirred. At this stage, a pale yellow polyamide solution was obtained. Then, after setting the stirring speed to 200 rpm, the polyamide solution in the 2L separable flask was heated to 190°C. During the temperature rise process, it was confirmed that when the liquid temperature was between 120 and 140°C, there was precipitation of polyimide resin powder and dehydration accompanying the imidization. After maintaining at 190°C for 30 minutes, let it cool to room temperature and filter. The obtained polyimide resin powder was washed and filtered with 300g of 2-(2-methoxyethoxy)ethanol and 300g of methanol, and then dried in a dryer at 180°C for 10 hours to obtain 317g of crystallinity. Powder of thermoplastic polyimide resin 1 (hereinafter also referred to as "polyimide resin 1"). When the IR spectrum of polyimide resin 1 was measured, it was confirmed that the characteristic absorption of the amide imine ring was present at ν (C=O) 1768 and 1697 (cm ^-1 ). The logarithmic viscosity is 1.30dL/g, the Tm is 323°C, the Tg is 184°C, the Tc is 266°C, the crystallization heat release is 21.0mJ/mg, the semi-crystallization time is less than 20 seconds, and the Mw is 55,000.

Table 1 shows the composition and evaluation results of polyimide resin 1 in Production Example 1. In addition, the molar % of the tetracarboxylic acid component and the diamine component in Table 1 are values calculated from the amounts of each component added when producing the polyimide resin.

[Table 1] Tetracarboxylic acid components (mol% of all tetracarboxylic acid components) Diamine component (mol% of all diamine components) (1)/[(1)+(2)] (mol%)*1 Tm(℃) Tg(℃) Tc (℃) Crystallization heat release ΔHm (H/mg) Half-crystallization time (seconds) Mw PMDA 1,3-BAC OMDA Manufacturing example 1 Polyimide resin 1 100 35 65 35 323 184 266 21.0 <20 55,000 *1: Content ratio of the repeating structural unit of formula (1) in polyimide resin 1 relative to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) (mol%)

The abbreviations in Table 1 are as follows. ・PMDA;pyromellitic dianhydride ・1,3-BAC; 1,3-bis(aminomethyl)cyclohexane ・OMDA; 1,8-hexamethylenediamine

Example 1 (Preparation and evaluation of polyimide resin composition and molded article) The powder of the polyimide resin 1 obtained in Production Example 1 and the amorphous resin (B1) ("ULTEM Resin 1000P" manufactured by SABIC, Tg: 217°C) were dry-blended in the proportions shown in Table 2. , using a co-rotating two-axis kneading extruder ("HK-25D" manufactured by PARKER CORPORATION, screw diameter 25mmΦ, L/D=41), the barrel temperature is 370°C and the screw speed is 150rpm for melting, kneading and extrusion. . The strands extruded from the extruder are air-cooled and then pelletized using a pelletizer ("FAN-CUTTER FC-Mini-4/N" manufactured by HOSHIPLA INCORPORATED COMPANY). The obtained pellets were dried at 150°C for 12 hours and then used for injection molding. Injection molding was performed using an injection molding machine ("ROBOSHOT α-S30iA" manufactured by FANUC CORPORATION) with a barrel temperature of 385°C, a mold temperature of 165°C, and a molding cycle of 60 seconds. The samples were cut into predetermined sizes to produce water absorption and CTE measurements. Injection molded body. Using the obtained injection molded article, various evaluations were performed by the above-mentioned methods. The results are shown in Table 2.

Examples 2~4 The types and amounts of the amorphous resin (B) shown in Table 2 were used, and the proportions shown in Table 2 between the amorphous resin and the powder of the polyimide resin 1 obtained in Production Example 1 were used. An injection molded body was produced in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 2.

Comparative example 1 The powder of polyimide resin 1 obtained in Production Example 1 was melt-kneaded and extruded using LABO PLASTOMILL (manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a barrel temperature of 360° C. and a screw rotation speed of 150 rpm. The strands extruded by the extruder are air-cooled and then pelletized using a pelletizer ("FAN-CUTTER FC-Mini-4/N" manufactured by HOSHIPLA INCORPORATED COMPANY). The obtained pellets were dried at 150°C for 12 hours and then used for injection molding. Injection molding was performed using an injection molding machine ("ROBOSHOT α-S30iA" manufactured by FANUC CORPORATION) with a barrel temperature of 350°C, a mold temperature of 200°C, and a molding cycle of 50 seconds. It was cut into a predetermined size and produced for water absorption and CTE measurements. Injection molded body. Using the obtained injection molded article, various evaluations were performed by the above-mentioned methods. The results are shown in Table 2.

Comparative example 2 Amorphous resin (B1) ("ULTEM Resin 1000P" manufactured by SABIC) was melt-kneaded and extruded using LABO PLASTOMILL (manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a barrel temperature of 360°C and a screw rotation speed of 150 rpm. The strands extruded by the extruder are air-cooled and then pelletized using a pelletizer ("FAN-CUTTER FC-Mini-4/N" manufactured by HOSHIPLA INCORPORATED COMPANY). The obtained pellets were dried at 160°C for 6 hours and then used for injection molding. Injection molding was performed using an injection molding machine ("ROBOSHOT α-S30iA" manufactured by FANUC CORPORATION) with a barrel temperature of 350°C, a mold temperature of 180°C, and a molding cycle of 60 seconds. The mold was cut into a predetermined size and used for water absorption and CTE measurements. Injection molded body. Using the obtained injection molded article, various evaluations were performed by the above-mentioned methods. The results are shown in Table 2.

Comparative example 3 Amorphous resin (B2) ("EXTEM Resin VH1003" manufactured by SABIC Corporation) was used in an injection molding machine ("ROBOSHOT α-S30iA" manufactured by FANUC CORPORATION) at a barrel temperature of 370°C, a mold temperature of 160°C, and a molding cycle of 60 seconds. Injection molding is performed, and the injection molded body is cut into a predetermined size to produce an injection molded body for measuring water absorption and CTE. Using the obtained injection molded article, various evaluations were performed by the above-mentioned methods. The results are shown in Table 2.

Comparative example 4 Amorphous resin (B3) ("SILTEM resin STM1700" manufactured by SABIC Corporation) was used in an injection molding machine ("ROBOSHOT α-S30iA" manufactured by FANUC CORPORATION) at a barrel temperature of 370°C, a mold temperature of 160°C, and a molding cycle of 60 seconds. Injection molding is performed, and the injection molded body is cut into a predetermined size to produce an injection molded body for measuring water absorption and CTE. Using the obtained injection molded article, various evaluations were performed by the above-mentioned methods. The results are shown in Table 2.

[Table 2] Comparative example 1 Example 1 Example 2 Comparative example 2 Example 3 Comparative example 3 Example 4 Comparative example 4 Resin composition (A) Polyimide resin 1 mass % 100 50 30 50 50 (B1)1000P mass % 50 70 100 (B2)VH1003 mass % 50 100 (B3)STM1700 mass % 50 100 Mass ratio (A)/[(A)+(B)] - 1.00 0.50 0.30 0 0.50 0 0.50 0 Evaluation results Glass transition temperature (Tg) ℃ 184 181 - 185 239 243 - - Crystallization temperature (Tc) ℃ 266 266 - - 266 - - - Crystallization heat release (ΔHm) ℃ 21.0 16.3 - - 9.0 - - - water absorption % 0.128 0.165 0.174 0.184 0.195 0.320 0.150 0.189 CTE(MD)150-210℃ ppm/℃ 130 48 -27 53 - - - - CTE(TD)150-210℃ ppm/℃ 102 -5 48 58 - - - - CTE(MD)150-220℃ ppm/℃ 130 - - 46 49 twenty four -195 CTE(TD)150-220℃ ppm/℃ 102 - - 53 62 8 16

The details of each component shown in Table 2 are as follows. ＜Polyimide resin (A)＞ (A1) Polyimide resin 1: Crystalline thermoplastic polyimide resin 1 obtained in Production Example 1 ＜Amorphous resin (B)＞ (B1) 1000P: "ULTEM Resin 1000P" manufactured by SABIC, an amorphous resin composed of repeating structural units represented by the above formula (B1), Tg: 185°C, MFR (temperature 337°C, load 6.6kgf): 9g/ 10 points (B2) VH1003: "EXTEM Resin VH1003" manufactured by SABIC, an amorphous resin composed of repeating structural units represented by the above formula (B2), Tg: 243°C, MFR (temperature 367°C, load 6.6kgf): 15.5g /10 points (B3) STM1700: "SILTEM resin STM1700" manufactured by SABIC, an amorphous resin composed of repeating structural units represented by the above formula (B3), MFR (temperature 295°C, load 6.6kgf): 7g/10 minutes

As shown in Table 2, the molding system composed of the polyimide resin composition (Examples 1 to 4) of the present invention has a lower thermal expansion coefficient and excellent dimensional stability compared to the molded bodies of Comparative Examples 1 to 4. In addition, it was found that the water absorption rate was also lower compared to the molded article of the amorphous resin (B) alone.

Furthermore, using the pellets obtained in Example 2, the dispersion state of the polyimide resin (A) and the amorphous resin (B1) in the pellets was confirmed by the following method. The pellets obtained in Example 2 were sliced using a microtome ("EM UC 7" manufactured by LEICA MICROSYSTEMS) as shown in Figure 1 along the direction perpendicular to the flow direction (MD) of the pellets (that is, the TD cross section was exposed) cut off. In Figure 1, 1 is a pellet. The cross section was stained with ruthenium tetroxide in the gas phase for 30 minutes, and then observed using a field emission scanning electron microscope (FE-SEM, "GeminiSEM500" manufactured by ZEISS) with an acceleration voltage of 1 kV and an observation magnification of 30,000 times. (Figure 2). In the observed image, it was judged that the dark-colored portions (islands) were composed of polyimide resin (A) that is not easily stained by ruthenium tetroxide. From Figure 2, it can be seen that in the pellets obtained in Example 2, the polyimide resin (A) and the amorphous resin (B1) form a sea-island structure. [Industrial applicability]

The polyimide resin composition and molded article of the present invention have a low thermal expansion coefficient and excellent dimensional stability, and are suitable for use in films, copper-clad laminates, and electrical and electronic components that require low thermal expansion coefficients, for example.

without

[Figure 1] A schematic diagram showing a method of preparing a sample for field emission scanning electron microscopy (FE-SEM) observation. [Fig. 2] A microscopic photograph of a cross-section cut along a direction perpendicular to the flow direction (MD) of the polyimide resin composition (pellets) of Example 2 and observed by FE-SEM.

Claims (5)

A polyimide resin composition contains polyimide resin (A) and amorphous resin (B). The polyimide resin (A) contains repeating structural units represented by the following formula (1) and the following formula (2) The repeating structural unit represented by the formula (1), and the content ratio of the repeating structural unit of the formula (1) relative to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is 20 to 70 mol %, the amorphous resin (B) contains repeating structural units represented by the following formula (I); R ₁ is a divalent group having 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure; R ₂ is a divalent chain aliphatic group having 5 to 16 carbon atoms; X ₁ and X ₂ are each independently A tetravalent radical with a carbon number of 6 to 22 containing at least one aromatic ring; R ₄ is a divalent group with 6 to 22 carbon atoms containing at least one aromatic ring; R ₅ is at least one of the divalent groups represented by any one of the following formulas (R-5a) to (R-5c) ; R ₅₁ is an alkyl group with 1 to 4 carbon atoms, an alkenyl group with 2 to 4 carbon atoms, or an alkynyl group with 2 to 4 carbon atoms; m ₅₁ is an integer of 0 to 2 independently, and p ₅₁ is an integer of 0 to 4 integer; * represents atomic bond; R ₅₂ is each independently an alkyl group with 1 to 4 carbon atoms, an alkenyl group with 2 to 4 carbon atoms, or an alkynyl group with 2 to 4 carbon atoms; m ₅₂ is each independently an integer from 0 to 2, p ₅₂ They are each independently an integer from 0 to 4; * represents an atomic bond; R ₅₃ is each independently an alkyl group or phenyl group having 1 to 4 carbon atoms; m ₅₃ is each independently an integer from 2 to 6; n is the average number of repeating structural units; * represents an atomic bond. The polyimide resin composition of claim 1, wherein in the formula (I), R ₄ is a divalent group represented by any one of the following formulas (R-4a) to (R-4c); In the above formula, * represents atomic bond. The polyimide resin composition of claim 1 or 2, wherein the absolute value of the thermal expansion coefficient of a 4 mm thick molded body obtained by molding the polyimide resin composition is measured in accordance with JIS K7197:2012 It is below 60ppm/℃. The polyimide resin composition according to any one of claims 1 to 3, wherein in the polyimide resin composition, the polyimide resin (A) is smaller than the polyimide resin (A). ) and the total mass of the amorphous resin (B), the mass ratio [(A)/{(A)+(B)}] is 0.01 or more and 0.99 or less. A molded body containing the polyimide resin composition according to any one of claims 1 to 4.

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